Colorado Highways: Routes 400 to 789

Quickjumps Directly to Routes

< 367 to 399

US400 402 US450 470 I-470 US491 US550 US560 US650 US666 789

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Location: North Front Range
Alignment: Link from US 287 north of Fort Collins east via Willox Lane to US 87

Became a state highway about 1950, and turned back by 1958.


Location: Eastern Arkansas Valley
Length*: 14.81mi
W End: Jct US 50-385 at Granada
E End: Kansas border concurrent with US 50 east of Holly (link to Richie Kennedy' site)
Nationally: E End: Jct I-44 near the KS-MO-OK border (488mi)

Counties: Prowers
Places: Granda, Holly

NHS: NHS for its entire length in Colorado by default, because US 50 is.

Scenic & Historic Byways: Santa Fe Trail America's Byways

Annual Average Daily Traffic (2008):

  • 2600 on US 50-400 at US 385, Granada
  • 2200 on US 50-400 east of Granada
  • 4100 on US 50-400 at 10th St., Holly
  • 1800 on US 50-400 at Kansas border

Notes: US 400 is a Congressional High Priority Corridor, brought to life in the early 1990s.

US 400 starts on US 50 at US 385 in Granada, and follows US 50 east into Kansas. It appears that when Kansas got US 400 and extended it into Colorado, CDOT ended it at the first opportunity available, which was Granada.

US 400, like I-238, makes roadgeeks reach for the Mylanta. US 400 is a recent addition to the system, and it does not fit into the numbering grid in any way whatsoever. Since it's a three-digit route, it should have a "parent" route, but it doesn't. Other recent US 4xx additions behave in a similar way.

Basically, it is a route to appease Kansas for not getting the proposed cross-continental I-66. Commissioned in 1994.

Related Site: US 400 Endpoints by Dale Sanderson


Location: Western Slope
Alignment: Link in Grand Junction from US 6 north via 1st Street to SH 386

Became a state highway about 1950 and turned back by 1954.


Location: Loveland (North Front Range)
Length*: 4.31mi
W End: Jct US 287 at 14th St. SE /Lincoln Ave. in south Loveland
E End: East frontage road at I-25 Exit 255 southeast of Loveland

Counties: Larimer
Places: Loveland

Roadway Names: 14th Street SE

Plans are afoot by CDOT to widen SH 402 to four lanes for its entire length. The timeline is unknown to me.

Annual Average Daily Traffic (2008):

  • 15,200 at US 287
  • 12,200 east of CR 9E
  • 12,700 at I-25

SH 402 starts at US 287, then heads due east on 14th St. SE to I-25. Along the way it passes the local CDOT shop and State Patrol office. SH 402 serves as the southern gateway into Loveland, while most people use US 34 two miles to the north.

Photo Gallery:

  • End SH 402. Good shot of the END marker on SH 402 at the I-25 underpass. Photo courtesy Chuck Doolittle.

Brought into the state system in about 1950. Paved by 1954.


Location: Western Slope
Alignment: Link from SH 340 east of Grand Junction north to US 6 at Clifton

Became a state highway about 1950. Turned back by 1954.


Location: South Western Slope > South Mountains > San Luis Valley > South Front Range
Length: 310mi
W End: Utah border on current US 666 northwest of Dove Creek
E End: Jct US 85-87 at Walsenburg
Nationally: Continued northwest via current US 491 and US 191 to US 50 at Crescent Jct., Utah (465mi)

US 450 is the original 1926 US route that went along current US 160 west from Walsenburg, then northwest on US 491 to Utah. The routing was different from today in two major areas: Near La Veta, US 450 went southwest into La Veta along current SH 12, then northwest, then continuing west on the present alignment. Northwest of Cortez also used to be different, as US 450 went north from Cortez to Dolores, west to Yellow Jacket, then continued northwest toward Dove Creek.

US 450 was renumbered as an extension of US 160 in 1934.

Related Site: Historic US 450 Endpoints by Dale Sanderson


Location: Southwest Metro Denver
Length*: 27.38mi
NW End: Jct US 6 in Golden
SE End: Jct I-25 Exit 194 at Lone Tree

Counties: Jefferson, Arapahoe, Douglas
Places: Golden, Lakewood, Morrison, Littleton, Highlands Ranch, Lone Tree

NHS: Entire length

Freeway: Entire length (exit list)

Roadway Names: C-470, pronounced "see four-seventy". No other Colorado highway is referred to as "C-xx". C-470 is the only one.

Notes: The ramp from EB I-70 to WB SH 470 should be open in fall 2005.

Milepost Guide:

  • -1.21: US 6/6th Avenue interchange, Golden (begin SH 470 in Jefferson County)
  • 0.00: I-70 Exit 260 interchange
  • 4.24: SH 8/Morrison Road interchange, Morrison
  • 5.69: US 285 interchange
  • 13.90: SH 121/Wadsworth Boulevard interchange
  • 15.44: SH 75/Platte Canyon Road
  • 15.85: Enter Arapahoe County
  • 16.56: Enter Douglas County
  • 17.00: US 85/Santa Fe Drive interchange, Littleton
  • 21.06: SH 177/University Boulevard interchange
  • 26.17: I-25 Exit 194 interchange, Lone Tree (end SH 470)

Annual Average Daily Traffic (2008):

  • 19,800 at US 6
  • 72,100 southeast of I-70
  • 75,200 southeast of SH 8/Morrison Rd.
  • 58,700 southeast of Quincy Ave.
  • 54,100 southeast of Bowles Ave.
  • 47,400 east of Ken Caryl Ave.
  • 69,000 east of SH 121/Wadsworth Blvd.
  • 75,200 east of US 85/Santa Fe Dr.
  • 90,500 east of Broadway
  • 107,000 east of Quebec St.
  • 88,800 at I-25

SH 470 forms the southwestern part of Denver's beltway. It has a 65mph speed limit almost the whole way.

The northwest end is a partial interchange at US 6 (6th Avenue) in Golden. There are direct ramps for NB 470 to WB 6 and EB 6 to SB 470. The other two movements are done at a signal on US 6. From there, SH 470 goes south 0.9mi, much of it elevated, to I-70. That is also a partial interchange, with two movements not allowed, WB 70 to WB 470 and EB 470 to EB 70. SH 470 used to have its north end there, so that's the reason for that. The interchange features a C-D road along westbound SH 470 to separate traffic going to I-70.

From I-70, SH 470 heads south and southeast via the east side of the Hogback. It is six lanes wide, paved in concrete. At the interchange for Morrison Road (SH 8), it changes from six lanes wide to four. SH 470 then continues along the east side of the Hogback, and south of Ken Caryl Avenue it turns to the east. Along the way is a full cloverleaf at US 285 (Hampden Avenue). East of Wadsworth, SH 470 goes past the north side of Chatfield Reservoir and crosses over the South Platte River. There, according to Jack Unitt, SH 470 is actually on Corps of Engineers property (which built Chatfield) and the state has only a lease to operate the highway. At the interchange with Santa Fe Drive (US 85) SH 470 begins climbing up a steep hill out of the Platte Valley, and then from there on to I-25 it continually rises and falls over the rolling terrain.

East of Santa Fe Drive SH 470 is in the north part of Douglas County, and passes by the north edge of Highlands Ranch. At Quebec Street, SH 470 picks up another lane, and is six lanes wide from there to I-25. The interchange with I-25 is a four-level stack interchange. One bad thing about the interchange is there is no access from SH 470 to County Line Road. So, if you want to go to Park Meadows Mall or Inverness, you have to get off at Yosemite Street.

Photo Gallery:

  • West or East US 6. The choice drivers make at the northwest end of SH 470 at Sixth Avenue/US 6. (June 2003)
  • Loop Advisory Speed. A unique advisory speed sign on the ramp from westbound SH 470 to westbound I-70. (June 2003)
  • US 6/I-70 Signs. Overhead signs as westbound SH 470 is climbing a hill approaching I-70. (June 2003)
  • Northwest of Morrison. Westbound SH 470 on its six-lane section northwest of Morrison. The overpass in the distance is Alameda Parkway. Off to the right you can see the Centennial Bike Trail and Rooney Road. (June 2003)
  • Morrison Exit. Westbound at the two-lane exit for Morrison Road. Photo by Drew Willsey. (July 2003)
  • Approaching Morrison Exit. Westbound SH 470 between US 285 and Morrison Road, with the Soad Lakes area of Bear Creek Park off to the right side. Photo by Drew Willsey. (July 2003)
  • US 285 Signs. Overheads signs on westbound SH 470 for US 285 at its cloverleaf interchange. The overpass is for Quincy Avenue. (June 2003)
  • Wadsworth Boulevard. Westbound SH 470 approaching the offramp to Wadsworth Boulevard/SH 121. (June 2003)
  • West of Quebec. Westbound SH 470 as it crosses the rolling terrain of northern Dougals County west of Quebec Street. (June 2003)
  • EB SH 470/I-25. Overhead signage on eastbound SH 470 approaching its end at I-25/E-470. (June 2001)
  • I-25/SH 470 Stack Interchange. View of the I-25/SH 470/E-470 stack interchange, as seen approaching it on westbound E-470. (May 1999)

SH 470 is the result of the demise of I-470. In the late 1960s, an I-470 was proposed for the southwest part of the metro, but due to land use and air quality concerns, it was scrapped. The federal funding that had been committed to it was transferred to other transportation projects, including construction of a "southwest parkway", what would become SH 470.

A section of what would ultimately become SH 470 was actually complete way back in 1957, from Platte Canyon Road (SH 75) east to Santa Fe Drive (US 85). How it was marked, I don't know. That section included an interchange at Santa Fe Drive by 1970.

Beginning in 1970, while CDH was trying to figure out what to do with I-470, they temporarily put an SH 470 along County Line Road from Santa Fe Drive to I-25. At that time, County Line Road was gravel from University to I-25, but was paved by 1972. By 1984, CDH was four-laning County Line Road, from Quebec east to I-25.

The first major portion of the SH 470 freeway to open was from Santa Fe Drive to I-25, in 1986. In 1989, more opened from Platte Canyon northwest to Ken Caryl, and from I-70 southeast to US 285. The gap between US 285 and Ken Caryl was completed in 1991.

The section between I-70 and US 6 opened the last week of August 2000. Previous to that section opening, coming north on SH 470 there was absolutely no good way to get to Golden from it. Backtracking was involved no matter what way you tried to take. But drivers still could not go from I-70 to westbound SH 470 or from eastbound SH 470 to I-70.

Work to construct additional movements at the I-70/SH 470 interchange took a tragic turn on May 15, 2004. Several nights before, workers had set a heavy steel girder along side the WB 470 bridge over I-70, as part of a new C-D road. That Saturday morning, the girder sagged onto the EB I-70 lanes and a vehicle with a family of three hit the girder, killing all of them.

The ramp from EB 470 to WB I-70 opened in February 2005. The loop ramp from EB I-70 to WB 470 and its necessary C-D road opened April 2006.

A new interchange at Alameda Pkwy opened in June 2008. The interchange was not put in by CDOT, instead it was funded by Lakewood, Jefferson County and the Green Tree Metropolitan District.

The full history dealing with the withdrawl of I-470 can be found on the Denver's 470 Saga page.

Add a third lane in each direction from I-25 to Wadsworth Blvd.


Location: Southwest Metro Denver
Length*: 24.80mi
NW End: Jct I-70 west of Denver
SE End: Jct I-25 south of Denver

I-470 is an Interstate highway that was never built. The short story is that in the late 1960s, an I-470 was proposed for the southwest part of the metro, but due to land use and air quality concerns, it was scrapped. But, there were funds set aside for it which had to be dealt with ($175.87M, $158.29M of which was federal). On December 17, 1976, the I-470 Ad Hoc Commission, appointed by Gov. Dick Lamm, passed a resolution stating

  • Pursuant to 23 USC 103(e)(4), I-470 should be withdrawn from the Interstate and Defense Highway System and its funds be transferred to other transportation projects.
  • Build a "parkway" along one of the route alternatives considered for I-470 (federal share $59.3M).
  • Make improvements to South Santa Fe Dr. (US 85) at a cost of $34.4M (federal share $27.5M). Improvements would include interchanges and eleven railroad grade separations. However, Santa Fe should not be expanded past six lanes to encourage public transit.
  • Make improvements to South Kipling Street at a cost of $12.8M (federal share $9.6M). Improvements include expanding Kipling to four lane arterial and extending it south to the new Parkway.
  • Transfer the remaining $61.2M in federal funds to other transportation projects, to be determined through the Metropolitan Planning Organization (part of Denver Regional Council of Governments), with concurrence of the Governor and CDH.

CDH passed a resolution accepting the Ad Hoc Commission's recommendations on January 20, 1977. The FHWA approved June 23, 1977.

For a much longer write-up, go to the Denver's 470 Saga page.


Location: Southern Western Slope
Length*: 69.60mi
S End: New Mexico border south of Cortez (link to Steve Riner's site)
N End: Utah border northwest of Dove Creek
Nationally: S End: I-40 at Gallup, New Mexico; N End: US 191 at Monticello, Utah (194mi)

Counties: Montezuma, Dolores
Places: Cortez, Lewis, Yellow Jacket, Dove Creek

NHS: Entire length in Colorado.

Expressway: South side of Cortez.

Spur Connection: From US 491 southeast along Piņon St. to US 160 in Cortez

Scenic & Historic Byways:

  • Trail of the Ancients (while concurrent with US 160) America's Byways
  • Trail of the Ancients (SH 184 to Pleasant View) America's Byways

Milepost Guide:

  • 0.00: New Mexico border (begin US 491 in Montezuma County)
  • 6.42: South jct US 160 south of Cortez
  • 26.22: North jct US 160/Main St., Cortez
  • 26.72: Spur US 491/Piņon St.
  • 36.80: SH 184 southeast of Lewis
  • 49.65: Enter Dolores County
  • 63.27: SH 141 west of Dove Creek
  • 69.60: Utah border (end US 491)

Annual Average Daily Traffic (2008):

  • 3400 at New Mexico border
  • 6500 on US 160-491 north of Towaoc
  • 15,600 on US 160-491 southwest of US 491, Cortez
  • 11,400 north of US 160/Spur 491
  • 4400 northwest of SH 184
  • 3500 northwest of CR Y, Yellow Jacket
  • 4500 at Main St., Dove Creek
  • 2400 west of SH 141
  • 2100 at Utah border

US 491 just catches the southwestern corner of the state. From New Mexico, it heads north through the Ute Mountain Ute Indian Reservation, picking up US 160. Together, US 160-491 head north on a mostly straight alignment with a speed limit slowdown at the turnoff to Towaoc, then come into Cortez, going down Broadway. At Main St. on the west side of town, US 491 continues north, while US 160 turns east through downtown. After leaving Cortez, US 491 goes northwest on its way to Utah, along the way through Lewis, Yellow Jacket, Pleasant View, Cahone, and Dove Creek, of which Dove Creek is the largest.

Photo Gallery:

  • New Mexico Border. Northbound at the New Mexico border crossing into Colorado. Photo by David Herrera. (October 2011)
  • Old US 666, New US 491. A sign on SH 141 advising of the then-upcoming renumbering. Photo by Steve Riner. (June 2003)
  • US 160-491 Truck Speed Limit. This section of US 160-491 south of Towaoc has a lower truck speed limit. (September 2011)
  • Towaoc Turnoff. US 160-491 northbound at the Towaoc turnoff and Ute Mountain Casino. (September 2011)
  • US 160 Spilt Northbound. Overhead signs on Broadway in Cortez approaching the US 160-491 split. (September 2011)

US 491 was born when the entire length of US 666 was renumbered in 2003. The change happened as a result of efforts of New Mexico. Governor Bill Richardson started a campaign to fix geometric problems with the highway and widen it, and he launched an effort to change US 666's number. He piggybacked the effort to renumber it on the effort to reconstruct it as way to get more exposure for the campaign. New Mexico officials also said the number scared off potential tourists, so a number change was seen as an economic development tool. CDOT polled southwestern Colorado residents and governments in 1999 about changing the name, and the only officials to respond, from Dove Creek and Dolores County, didn't have an opinion on renumbering it. But CDOT said they wouldn't mind changing the number so they didn't have to keep replacing stolen signs.

New Mexico, Colorado and Utah submitted the change to AASHTO in spring 2003, proposing to renumber US 666 to US 393. However, AASHTO did the right thing and rejected that number since it didn't fit the numbering grid. The states then agreed to 491, since it connects to US 191 in Utah and one or more states already had highways numbered 291 and 391. AASHTO made the change official May 31, 2003, and it took affect in Colorado on July 1, 2003.

See US 666 and US 393 for more.

Location: Southern Western Slope > West Central Mountains
Length*: 130.22mi
S End: New Mexico border northeast of Aztec (link to Steve Riner's site)
N End: Jct US 50 at Townsend Ave./San Juan Ave. in Montrose
Nationally: S End: Jct I-25 at Bernalillo, New Mexico (304mi)

Counties: La Plata, San Juan, Ouray, Montrose
Durango, Hermosa, Coal Bank Pass, Molas Pass, Silverton, Red Mountain Pass, Ouray, Ridgway, Montrose

NHS: Entire length in Colorado.


  • For about 1 mile north of the New Mexico border
  • Concurrent with US 160 on the south side of Durango
  • North side of Durango
  • 5-lane undivided for about 4 miles near Durango Mountain Resort ski area
  • South side of Montrose
Roadway Names: San Juan Skyway or Million Dollar Highway, from Durango to Ridgway

Mountain Passes:

  • North of the La Plata/San Juan County line, Coal Bank Pass (10,640ft, 6.5% grade) (not shown on some maps)
  • South of Silverton, Molas Pass (10,910ft; 7% grade).
  • North of Silverton, Red Mountain Pass (11,118ft; 7+% grade).

CDOT has plans to four-lane US 550 from the New Mexico border north to US 160.

Scenic & Historic Byways: San Juan Skyway (US 160 to SH 62) America's Byways (All-American Road)

Milepost Guide:

  • 0.00: New Mexico border (begin US 550 in La Plata County)
  • 16.56: South jct US 160 southeast of Durango
  • 20.92: North jct US 160, Durango
  • 49.87: Enter San Juan County
  • 70.37: SH 110, Silverton
  • 80.18: Enter Ouray County, Red Mountain Pass
  • 103.70: SH 62, Ridgway
  • 117.53: Enter Montrose County
  • 129.25: SH 90/Main St, Montrose
  • 130.22: US 50 (end US 550)

Annual Average Daily Traffic (2008):

  • 8200 at New Mexico border
  • 5700 north of CR 310
  • 8000 south of US 160
  • 38,900 on US 160-550 at Turner Dr, Durango
  • 32,700 north of US 160
  • 13,400 north of Hospital St.
  • 3800 north of CR 250
  • 2000 north of Durango Mountain Resort ski area
  • 2000 north of SH 110, Sliverton
  • 5200 at 6th Ave., Ouray
  • 4300 north of CR 23
  • 7300 north of SH 62, Ridgway
  • 7300 north of CR 24
  • 9100 north of CR T
  • 26,700 at Oakgrove Rd, Montrose
  • 23,400 at SH 90

US 550 starts south of Durango at the New Mexico line, and then follows the Animas River north through the Southern Ute Indian Reservation. It climbs up a ridge above the east side of the valley for the Animas River, then just south of US 160 makes a sudden,, steep descent down to that highway. US 160 and 550 head northwest on a four-lane highway toward the south side of Durango. On the south edge of downtown US 160 turns west off US 550 toward Cortez while US 550 goes north into the main part of town on Camino del Rio. Camino del Rio just barely skirts the west edge of downtown, allowing US 550 to bypass the congestion of downtown. At 14th St. US 550 picks up Main Ave. and heads north through Durango on that.

After leaving Durango, US 550 continues north up the Animas River valley through Trimble, Hermosa, and Rockwood. US 550 then leaves the Animas River and blazes its own alignment, beginning to climb a steep, long grade up to Coal Bank Pass. Southbound descending the pass features one truck runaway ramp. North of Coal Bank's summit US 550 doesn't really descend a whole lot, instead it jumps up to Molas Pass.

Heading north down Molas Pass US 550 then again picks up the canyon for the Animas River and hugs the side of it as it drops down to Silverton. US 550 doesn't really enter Silverton, instead turning northwest away from it at an intersection on the south side of town. The highway then uses the canyon for Mineral Creek as it climbs up to Red Mountain Pass. It is one of the passes in Colorado most likely to be closed in winter due to storm and avalanche conditions. Just to the north side of Red Mountain Pass is the Red Mountain Mining Area, a mining boom town from the late 1800s. An overlook provides signs with historical info and gives a view of the structures.

From Red Mountain Pass US 550 uses Red Mountain Creek for a while, briefly passing through an alpine meadow valley. Between there and Ouray, US 550 goes through the Uncompahgre Gorge, where it hugs the east side canyon wall, passing through a snowshed (avalanche protection) and hard rock tunnel. The highway then goes through Ouray on 3rd St., and follows the Uncompahgre River northwest. US 550 follows the Umcompahgre all the way to Montrose, passing through Ridgway and Colona along the way. In Montrose, US 550 comes into town on Townsend Ave., and at the intersection with San Juan Ave north of downtown ends at US 50.

Photo Gallery:

  • US 160-550 Markers. A marker assembly on southbound US 550 approaching US 160 on the south side of Durango. (July 2005)
  • Main Ave at 15th St. Northbound US 550 on Main Ave in north Durango at 15th St. Just ahead is the bridge over the Las Animas River. (September 2011)
  • DSRR Chugging North. Northbound on US 550 at Trimble, a shot of the Durango & Silverton Railroad scenic steam train chugging north. (September 2011)
  • Hermosa Cliffs and Engineer Mountain. Northbound US 550 north of Trimble, with the Hermosa Cliffs to the left and 12,968' Engineer Mountain in the distance. (September 2011)
  • Runaway Truck Ramp. A runaway truck ramp on southbound US 550 at Milepost 52, on the descent from Coal Bank Pass. (July 2005)
  • Engineer Mountain. A view looking along southbound US 550 as is goes down the south side of Coal Bank Pass. The peak in the distance is Engineer Mountain, which dominates the skyline in this area. (July 2005)
  • North of Coal Bank Pass. A view of US 550 descending down the north side of Coal Bank Pass. (July 2005)
  • Molas Southbound Descent. View down southbound US 550 as it descends the south side of Molas Pass. (September 2011)
  • Molas Pass Summit MarkerNorthbound View. Two shots at the rest area at the summit of Molas Pass. One is the marker sign, the other looking northerly across the Molas Park alpine meadown. (September 2011)
  • Silverton Overlook. A pullout on US 550 just south of Silverton that affords a great view of the town below, visble behind the bikers. (September 2011)
  • CR 110-2 Silverton Turnoff. Northbound US 550 where it curves left, or you can go straight and end up on Silverton's main drag. (September 2011)
  • South Red Mountain Descent. North of Silverton, a view down southbound US 550 on Red Mountain Pass' south descent. (September 2011)
  • Red Mountain Pass Marker. The US Forest Service marker at the top of Red Mountain Pass. (July 2005)
  • Red Mountain Pass Summit. The view looking south along US 550 from the top of Red Mountain Pass. (July 2005)
  • North Red Mountain Switchbacks. A shot of a convoy of bikers navigating a pair of switchbacks on Red Mountain Pass' north side. Reminds me of an asphalt snake. (September 2011)
  • Snowshed. Here US 550 passes through a snowshed, a structure that provides avalanche protection in the winter. When this picture was taken there was still snowmelt going on, because an active stream was flowing over the top of the snowshed. (July 2005)
  • Uncompahgre Gorge. US 550's most notable section, south of Ouray where the road has been blasted into the mountainside about 200' above the Uncompahgre River. (September 2011)
  • Hard Rock Tunnel. An unlined hard rock tunnel, as viewed on southbound US 550 a couple miles south of Ouray. (July 2005)
  • Ouray. A good view of Ouray, looking north on US 550 as it passes through town. (July 2005)
  • North of Ouray. Southbound US 550 at Milepost 98, a few miles north of Ouray, as the canyon for the Uncompahgre River begins to rapidly narrow. (July 2005)
  • Milepost 116. Southbound US 550 south of the Montrose/Ouray County line, with the San Juan Mountains looming on the horizon. (July 2005)

US 550 is an original 1926 US highway in Colorado, but originally only went from Montrose to Durango. It was extended south to New Mexico in 1935. Also, the north end in Montrose originally used Chipeta Road north then east into town on current SH 90. It was moved to its current alignment heading south out of town about 1936.

By 1938 the only unpaved portion was from Rockwood to Ouray. By 1954 the only sections not paved were over Molas Divide and Red Mountain Pass. Red Mountain Pass was paved by 1955 and Molas Divide by 1957. The Durango southwest bypass opened by 1982.

US 550 follows the so-called Million Dollar Highway between Silverton and Ouray. It was first built as a toll road by Otto Mears. In the first year of construction, 1882, he managed to get the first 8.5mi at a cost of $40,000/mile. He had to contend with sheer rock walls over 1,000 feet high, and had to blast a shelf for the road into that rock. He placed a toll booth at Bear Creek Falls. In 1882-83, he extended the road further south, following Red Mountain Creek, over Red Mountain Pass, and down Mineral Creek to Silverton.

The state took over the Million Dollar Highway in the 1920s, and spent over $550,000 for improvements during the 1920s and 30s. The Bureau of Public Roads had already paid out a considerable amount of money for forest highway funds. The urban legend is that it is called the Million Dollar Highway because when the state resurfaced it, gravel was used that had gold in it. There is no proof of this.

In May 2010 the US 50 reroute onto San Juan Ave in Montrose took place. Previously US 50 came south on Townsend Ave and east on Main St, meaning that intersection was a turn in US 50 as well as the end for US 550 and SH 90. CDOT moved US 50 onto San Juan around the northeast side of downtown and turned back Main St east of Townsend to the city, and extended US 550 from Main up to San Juan to meet US 50.

Four-lane US 550 from SH 62 north to Montrose.

Related Site: US 550 Endpoints by Dale Sanderson. Neat photos!

US 560 is a number that was proposed when the US Highway system was being developed in 1926, but it didn't make the cut when the system was implemented in 1927. Due to US 60 being changed to US 66 in the final plan, US 560 was renumbered to US 666. See US 666 below and US 491 above for more.


Location: Central Mountains
Length: 23mi
S End: Jct US 50 at in Salida
N End: Jct US 40S at current US 24-285 intersection south of Buena Vista

US 650 was commissioned in 1928 along the route of what is now SH 291 and US 285 from Salida to Buena Vista. The route due north from Poncha Springs was not built until the 1940s, so previously one had to use current SH 291 northward from Salida. US 650 was decommissioned in 1935 in favor of a new US 285 coming south from Denver.

Related Site: Historic US 650 Endpoints by Dale Sanderson


Location: Southern Western Slope
Length: 1927-1970: 26mi; 1970-2003: 69.60mi*
S End: New Mexico border south of Cortez (link to Steve Riner's site)
N End: 1928-1970: Cortez; 1970-2003: Utah border northwest of Dove Creek

Roadway Names: Devil's Highway. Yes, it's actually been referred to as such in the media.

In the first 1926 US Highway plan, what is now US 491 from New Mexico to Cortez was numbered US 560, and from Cortez to Utah was numbered US 450. But by the time the plan was implemented in 1927 US 560 was renumbered to US 666, and by 1934 US 450 had been deleted and taken over by an extended US 160. US 666 was paved by 1939. US 666 had its north end at Cortez all the way up to the end of 1970, when US 160 was shifted to its current route and US 666 was extended northwest to Utah. US 666 was renumbered in its entirety to US 491 in summer 2003 as a result of New Mexico campaigning to improve conditions of the highway and its image.

Photo Gallery:

Related Site: Historic Endpoints in Cortez (including US 666) by Dale Sanderson


Location: Western Slope > Northern Mountains
Length: 396mi
S End: 1954-1960: New Mexico border concurrent with US 550; 1961-1984: New Mexico border concurrent with US 666
N End: Wyoming border concurrent with SH 13 (link to Andy Field's site)
Nationally: S End: Mexico border at Nogales, Arizona; N End: Canada border at Sweetgrass, Montana

Roadway Names: Canada-Mexico Highway

SH 789 is the former Canada-Mexico Highway, a highway numbered 789 from Mexico to Canada via the Rocky Mountain region. It was created in 1954 as kind of a pre-Interstate NAFTA highway. At first, no one knew what the deal was with Highway 789 in Wyoming (the only remaining portion of it), but eventually people figured out that at one time it had gone from Mexico to Canada but no one knew the reason. Then, in early 1998 I ran into this paragraph in The High Road by Marion Wiley:

...There was also a route from Dallas to Canada via Denver called the D.C.D. This followed the Great North and South Highway through Colorado, but reports indicate interest in this road lagged somewhat by the time it reached Montana. Years later, interest in a continuous north and south route was rekindled. A concerted drive resulted in signing U.S. 789 (now Colorado 789) which runs through far Western Colorado. This route was originally promoted as a Canada-to-Mexico Highway, running from Nogales, Arizona, to Sweet Grass, Montana.

(Keep in mind it was written in 1976). "Eureka!" was my reaction. I should note that no one has ever found any evidence that Multi-State 789 was marked as a US Highway, so this is probably an error on Mr. Wiley's part.

old 789 markerWhen first marked in 1955, SH 789 went from the New Mexico border south of Durango north on US 550, northwest on US 50, east on US 6-24 (later I-70), and north on SH 13 to Wyoming. By 1959 it was rerouted so it went from Durango west to Cortez, then entered New Mexico via US 666. (Old 789 marker photo at right from Lary Brown)

When was Multi-State 789 done away with? CDH maps show it up until at least 1984, then gone after that. However, this is only Colorado. As to what other states did about it, I only know of Wyoming, who kept it, because they numbered several sections of highway as WY 789 exclusively, rather then running the number concurrently with whatever the normal designation of the highway was, like Colorado did.

This is an excerpt of the legend from the 1974 official CDH map. SH 789 got this special mention on the CDH map legends on all of the maps from the '70s up until SH 789 disappeared after 1984.


Last updated 30 November 2014