Colorado Highways: US 6

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Location: Central Western Slope > Central Mountains > Metro Denver > Northeastern Plains
Length*: 235.78mi signed; 467.28mi implied
W End: Utah border on unmarked overlap with I-70 west of Fruita
E End: Nebraska border east of Holyoke (link to Chris Geelhart's site)
Nationally: W End: Jct US 395 in Bishop, California; E End: Tip of Cape Cod, Massachusetts (3205mi)

Counties: Mesa, Garfield, Eagle, Summit, Clear Creek, Jefferson, Denver, Adams, Weld, Morgan, Washington, Logan, Phillips
Places: Fruita, Grand Junction, Palisade, De Beque, Parachute, Rifle, Silt, New Castle, Gypsum, Eagle, Edwards, Avon, Silverthorne, Dillon, Loveland Pass, Clear Creek Canyon, Golden, Lakewood, Denver, Commerce City, Wiggins, Hillrose, Merino, Sterling, Fleming, Haxtun, Paoli, Holyoke


Freeway: US 40 southeast of Golden east to I-25 Exit 209 (exit list)


Spur Connection: From I-70 frontage road southeast to SH 82 in Glenwood Springs

Broken Route: Discontinuous due to these unmarked multiplexes with Interstates:

Mountain Passes: When I-70 goes through the Eisenhower Tunnel, US 6 leaves I-70 to go over Loveland Pass (11,992 feet; 6% grade)

Roadway Names:

Scenic & Historic Byways:
Notes: CDOT and Grand Junction have agreed at some point in the future for US 6 along North Ave to be turned back to the city. The turn back is in exchange for CDOT taking over ownership and maintenance of three bridges that will be built near US 50 as part of the city Riverside Parkway project. I assume this means at some point US 6 signing will disappear from North Ave.

Milepost Guide:

  • 11.21: I-70 Exit 11 interchange south of Mack (begin US 6 in Mesa County)
  • 15.13: SH 139, Loma
  • 19.78: SH 340/Aspen St., Fruita
  • 25.99: I-70 Exit 26 interchange west of Grand Junction
  • 30.27: BL 70 interchange, west Grand Junction
  • 34.37: BL 70, east Grand Junction
  • 37.49: BL 70, west of Clifton
  • 45.82: I-70 Exit 44 interchange northeast of Palisade (end US 6)
  • 62.31: On I-70 north frontage road at De Beque interchange (begin US 6 in Mesa County)
  • 66.26: Enter Garfield County
  • 72.28: I-70 Exit 72 West Parachute interchange
  • 88.90: I-70 Exit 87 interchange west of Rifle
  • 91.24: West jct SH 13, Rifle
  • 92.00: East jct SH 13/Railroad Ave., Rifle
  • 99.23: BS I-70/9th St., Silt
  • 110.79: I-70 Exit 109 interchange east of New Castle (end US 6)
  • 141.89: I-70 Exit 140 interchange, Gypsum (begin US 6 in Eagle County)
  • 149.66: BS I-70, Eagle
  • 159.18: West jct SH 131, Wolcott
  • 159. 57: East jct SH 131, Wolcott
  • 165.99: BS I-70, Edwards
  • 172.17: I-70 Exit 169 interchange, Eagle-Vail
  • 174.54: I-70/US 24 Exit 171 interchange, Dowds Junction (end US 6)
  • 208.65: I-70/SH 9 Exit 205 interchange, Dillon/Silverthorne (begin US 6 in Summit County)
  • 225.04: Enter Clear Creek County, Loveland Pass
  • 229.60: I-70 Exit 216 interchange east of Loveland Pass (end US 6)
  • 257.08: I-70 Exit 244 interchange east of Idaho Springs (begin US 6 in Clear Creek County)
  • 257.75: US 40, Clear Creek Canyon
  • 260.22: Enter Jefferson County
  • 260.27: SH 119, Clear Creek Canyon
  • 271.60: SH 58-93, west Golden
  • 275.12: US 40/BL 70/Colfax Ave. southeast of Golden
  • 275.65: I-70 Exit 261 interchange southeast of Golden
  • 279.33: SH 391/Kipling St. interchange, Lakewood
  • 280.83: SH 121/Wadsworth Blvd. interchange
  • 282.33: SH 95/Sheridan Blvd. interchange, Enter Denver County
  • 283.86: SH 88/Federal Bvd. interchange
  • 284.75: I-25 Exit 209 interchange (end US 6)
  • 290.98: I-70 Exit 276A at Steele Street, Denver (begin US 6 in Denver County)
  • 292.05: Enter Adams County
  • 292.14: South jct SH 2 interchange, Commerce City
  • 292.72: I-270 Exit 2 interchange, Commerce City
  • 293.67: North jct SH 2 interchange, Commerce City
  • 295.99: I-76 Exit 9 interchange, Commerce City
  • I-76 Exit 12: End US 6 signing
  • 343.52: I-76 Exit 64 interchange west of Wiggins (begin US 6 in Morgan County)
  • 345.92: SH 52/SH 39, Wiggins
  • 346.42: US 34 onramp
  • 346.69: I-76 Exit 66 interchange east of Wiggins (end US 6)
  • 371.69: I-76/Spur US 34 Exit 92 interchange east of Brush (begin US 6 in Morgan County)
  • 380.59: Enter Washington County
  • 387.94: Enter Logan County
  • 397.95: SH 63, Atwood
  • 404.45: SH 14/Main St., Sterling
  • 404.64: US 138/Chestnut St., Sterling
  • 406.56: I-76 Exit 125 interchange east of Sterling
  • 406.79: SH 61 east of Sterling
  • 434.41: Enter Phillips County
  • 436.49: SH 59/Washington Ave., Haxtun
  • 454.06: US 385/Interocean Ave, Holyoke
  • 467.28: Nebraska border (end US 6)

Annual Average Daily Traffic (2008):

  • 820 north of I-70, Mack
  • 2500 east of SH 139, Loma
  • 580 west of SH 340, Fruita
  • 23,200 northwest of I-70 Exit 26
  • 35,600 on BL 70 northwest of US 6 interchange
  • 27,000 east of 4th St., Grand Junction
  • 18,000 west of BL 70
  • 27,500 on BL 70 east of SH 141
  • 13,000 east of BL 70, Clifton
  • 3300 east of Main St., Palisade
  • 1200 at I-70 Exit 44
  • 980 southwest of Parachute
  • 7100 at I-70 connection, Parachute
  • 5000 at I-70 Exit 87 west of Rifle
  • 4800 east of SH 13, Rifle
  • 7300 west of BS 70, Silt
  • 2700 east of CR 214
  • 7100 at 7th St, New Castle
  • 1800 at I-70 Exit 109
  • 8200 at I-70 Exit 140, Gypsum
  • 13,500 west of BS 70, Eagle
  • 4000 west of SH 131
  • 11,800 west of BS 70, Edwards
  • 13,300 east of I-70 connection, Avon
  • 4900 at I-70/US 24 Exit 171
  • 25,800 at I-70/SH 9, Dillon/Silverthorne
  • 11,800 east of Elk Horn St./Tenderfoot St.
  • 4200 east of Elk Run Dr.
  • 1300 at I-70 Exit 216
  • 3000 at I-70 Exit 244
  • 13,300 east of SH 119, Clear Creek Canyon
  • 27,800 southeast of SH 58-93, Golden
  • 33,500 southeast of SH 470
  • 59,300 east of I-70 Exit 261
  • 110,000 east of SH 121/Wadsworth Blvd., Lakewood
  • 137,000 at I-25, Denver
  • 19,200 at I-70 Exit 276A
  • 47,100 on US 6-85/SH 2 south of I-270, Commerce City
  • 25,600 on US 6-85 north of SH 2
  • 18,500 at I-76 Exit 9
  • 980 at I-76 west of Wiggins
  • 3300 east of SH 39/52
  • 980 at I-76/Spur US 34 Exit 92 east of Brush
  • 720 northeast of CR R, Prewitt Reservoir
  • 3500 northeast of SH 63, Atwood
  • 3700 northeast of Front Street, Sterling
  • At US 138 in Sterling (on two one-way streets): 5100 northeastbound, 9900 southwestbound
  • 8800 east of US 138
  • 5800 east of SH 61
  • 1700 east of CR 91
  • 2300 west of SH 59, Haxtun
  • 1500 east of CR 21
  • 4400 east of US 385, Holyoke
  • 1000 east of CR 49
  • 3200 at Nebraska border

US 6 is either "on" I-70 or within a few miles of it from the Utah border to Denver. At first, I-70 has an unmarked multiplex with US 6-50, but US 6 breaks off at Mack (Exit 11) and parallels I-70 on I-70's north side southeast through Loma and Fruita toward Grand Junction.

At Exit 26, US 6 crosses over from the north to the south side of I-70 heading east, and US 50 exits and heads southeast concurrent with US 6. This is also the west end of Grand Junction's BL 70. US 6-50/BL 70 head southeast toward downtown, while I-70 has a bypass which heads east. The three routes head southeast as an expressway, and at North Ave., there is an interchange, and US 6 heads east along North Ave. while BL 70/US 50 continue southeast. US 6 continues due east along North Ave., and then joins BL 70 again at Fruitvale, northeast of downtown Grand Junction. The two continue northeast to Clifton, where US 6 breaks off again and heads east to Mount Lincoln and Palisade. US 6 goes east through Palisade on 8th St., then northeast, and joins I-70 with an unmarked overlap at Exit 44.

US 6 is officially on the I-70 frontage road from De Beque to west Rifle (Exit 62 to 87) but is only partially marked. There are a few scattered reassurance markers but only CDOT's route log definitively shows the frontage road as part of US 6.

From Exit 62 at De Beque, US 6 goes northeast along the north frontage road. The frontage road crosses over to I-70's south side, then back over to the north side at Exit 72, coming into Parachute on 1st Street. US 6 continues on the north frontage road, crosses over to the south side west of Rulison, then comes to the west Rifle interchange, Exit 87.

At Exit 87, US 6 continues to the north of I-70, and goes into Rifle. US 6 continues to parallel I-70's north side through the broad Colorado River valley through Silt and New Castle, all the way to Chacra, where it ends at Exit 109. Next, there is a Spur US 6 all by itself in Glenwood Springs, near Exit 116.

US 6 then becomes autonomous from I-70 again at Exit 140, and heads south into Gypsum, and then parallels I-70's south side through Eagle. US 6 then crosses over to I-70's north side, goes through Wolcott, crosses back to I-70's south side, through the ski tourist mecca area of Edwards and Avon, crosses back to I-70's north side, and ends at I-70 at Exit 171. Exit 171 is also US 24's west end.

At Exit 205 at Silverthorne, US 6 again breaks off of I-70, and heads east through Dillon, and then up and over Loveland Pass. Loveland Pass is used as the alternative for I-70 traffic that can't or won't go through the Eisenhower Tunnel. After coming down from Loveland Pass, US 6 ends at I-70 Exit 116, at the east Portal of the Eisenhower Tunnel.

At Exit 244, US 6 starts again and goes north off of I-70 and heads east via Clear Creek Canyon into Golden. There are six tunnels along US 6 in the Canyon, numbered heading west from Golden. However, Tunnel 4, at the SH 119 intersection, has been abandoned and boarded up. The US 6/SH 119 intersection improvement project in 1998 closed that tunnel, and replaced the previous Y intersection with a single signalized T intersection. Clear Creek Canyon tends to be a treacherous drive during winter weather. CDOT has improved US 6, repaving it and putting a rumble strip down the center stripe from Golden all the way west to I-70.

At Golden, US 6 hits an intersection at SH 58 and SH 93. Many, many maps show that as an interchange, but it is just an regular four-way intersection with a signal light. From that intersection, US 6 picks up as a multi-lane expressway on 6th Avenue southeast to the intersection at 19th St., where it becomes four-lane divided. It then turns east to a signal light at US 40/BL 70, then east of that US 6 becomes the 6th Avenue Freeway, which I have created an exit list for. I-70 Exit 261 is the last interchange on the west end of the 6th Ave. Freeway, but is only a partial interchange. One can only go from EB 70 to EB 6 and WB 6 to WB 70.

The 6th Ave. Freeway is six lanes wide, with a 65mph speed limit west of Sheridan. The freeway rises and falls to go over or under cross streets, because development lines the freeway, so there would not have been room to make the cross streets rise or fall. The freeway ends abruptly at I-25 Exit 209. If you continue straight, you go onto 6th Ave., a city surface street, with a 30mph speed limit.

US 6 goes unmarked north on I-25, to I-70, east on that to Exit 276A, where it heads northeast on Vasquez Blvd. concurrent with US 85. Vasquez is a divided expressway through Commerce City, and includes two partial interchanges each at the north and south SH 2 meeting places. US 6-85/SH 2 goes through a cloverleaf at I-270 Exit 2, then up to I-76 Exit 9. Together, US 85 and US 6 overlap onto I-76, but at Exit 12 US 85 breaks off toward Brighton and US 6 signing ends.

At Wiggins, US 6 has an unmarked loop south off of I-76 along Central Ave. from Exit 64 to Exit 66. It's not marked as any kind of state highway out in the field but it's defined as US 6 in the CDOT sources.

US 6 next exists autonomously from I-76 at Exit 92 northeast of Brush, then follows the South Platte River farm country parallel to I-76 northwest's side, going through Hillrose and Merino. At Atwood US 6 becomes a divided expressway until reaching the south side of Sterling. US 6 heads north into town on Division St., but then turns northeast on two one-way streets. Northeastbound traffic is on 3rd St., while SWB traffic has 4th St. At Chestnut St., US 6 turns east, while the two one-way streets continue northeast as US 138. From downtown Sterling, US 6 heads up a viaduct to get over the Sterling railyards, crosses the South Platte then goes through I-76 Exit 125.

From I-76 US 6 climbs east up and out of the South Platte valley and across sand hill terrain. The crossroads town of Fleming is crossed through as is a small grain elevator complex at Dailey. The terrain is pretty much flat at US 6 crosses into Phillips County and into Haxtun. US 6 uses 1st Street through town and intersects SH 59. US 6 continues to parallel a BNSF rail line to Paoli, another grain elevator complex with small town attached to it.

Holyoke's grain elevator is visible as the tallest thing for miles around, and US 6 passes it as it comes into town on Denver Street. In downtown US 6 meets US 385 at a signal, then heads due east to the Nebraska border.

If there ever was a highway in the US Highway System grid that was totally out of place, US 6 would be it. In the eastern part of the state, it starts off north of US 34, but then drifts southeast along the I-76 corridor until it's along US 40. Then it continues along I-70, until not only is it south of US 40, it's along the same route as US 50!

Photo Gallery:

This massive violation of numbering guidelines comes from the fact that US 6 in the western US is not an original 1920s US highway. Its route west of Chicago was originally made out of US 32 and US 38, but someone had the idea of making a coast-to-coast road named the Roosevelt Highway. In 1932, US 38 from the Nebraska border through Holyoke, Sterling, Fort Morgan and Greeley, was replaced with US 6. By 1938, US 6 was rerouted southwest of Wiggins, taking the route through Hudson and Commerce City into Denver. It was also extended west to Utah, via Mount Vernon Canyon, Georgetown, Loveland Pass, Frisco, Climax, Leadville, Minturn, Eagle, Glenwood Springs, Rifle, Grand Junction and Mack. At that time, the only section not paved was from Climax to Empire. Also, in Denver it used the routing of Colfax-Colorado-Vasquez heading east and northeast.

By 1940 US 6 was rerouted to follow SH 78 over Vail Pass, bypassing Minturn, Leadville and Climax. By 1946 the only section of US 6 not paved was over Loveland Pass. By 1947, US 6 was rerouted in Denver, using Colfax-Larimer-Broadway-Brighton-46th-Vasquez heading east and northeast. By 1949, US 6-50 was rerouted northwest of Grand Junction, utilizing a more direct route adjacent to the north side of railway; previously it "stairstepped" between Grand Junction and Fruita.

In 1952 a new section of US 6 opened through Clear Creek Canyon between Idaho Springs and Golden, and US 6 was moved off of the Mount Vernon Canyon alignment shared with US 40. The effort to build the road through Clear Creek Canyon started in 1933, but infighting among Governor Ed Johnson, CDH head Charles Vail, Denver Mayor Ben Stapleton and the feds delayed construction for years. Vail wanted to push for widening of US 40 and Stapleton wanted Clear Creek Canyon for reservoirs. Eventually US 6 would be built with federal WPA money and state money used for US 40. In 1937 construction started on US 6, but was slow at first. The railroad through the canyon needed to be used for the road, but the railroad hadn't abandoned its line yet. By 1941 a couple of the tunnels had been built, and that summer the railroad abandoned its line. The war stopped construction until 1945, but once started again, all but five miles were completed in 1950. The Clear Creek Canyon road was opened June 28, 1952. The preceding paragraph and historical info is courtesy Juston Fariello.

By 1954, US 6 was rerouted in Golden and Denver, utilizing the route of 6th Ave. east to Federal, then 8th-Broadway-Brighton-46th-Vasquez heading east and northeast, and Loveland Pass was paved.

In 1957, the state maps started differentiating 4-lane and 2-lane roads. US 6 is shown as 4 lanes from SH 58 east into Denver, on Vasquez, from Barr Lake to Hudson, and from Wiggins to Fort Morgan. Starting in 1960, the maps start differentiating between freeways, expressways, and two-lane roads. By then Idaho Springs freeway bypass is open, and US 6 is freeway from Federal Blvd. to the Valley Highway, and Roggen to Fort Morgan.

West of Denver, I-70 has commandeered much of US 6's route. US 6 served as a temporary I-70 while the Interstate was finished in segments here and there during the 1960's, '70s, and '80s. The sections of US 6 that I-70 did not take over are mentioned above. Northeast of Denver, I-80S (now I-76) took over much of US 6's route. For histories after 1960 having to do with when segments of I-70 and I-76 were completed, see those listings.

6th Avenue Freeway history: Expressway from Golden to Denver already by 1957; 1960 freeway west to Federal Blvd.; 1961 interchanges in at Wadsworth and Sheridan; 1963 freeway west to Wadsworth and partial interchange in at SH 58; 1965 freeway west to Kipling; 1966 freeway west to Simms.

As Stephen Levine chimes in on the 6th Avenue Freeway:

[T]he freeway was first a divided highway with at-grade, signalled intersections. In the late 50's, the signalled intersections were replaced with overpasses and underpasses and Sixth Avenue extended to meet the newly completed Valley Highway (now I-25, formerly US 87). Originally, US 6 was 8th Avenue and then west of Federal Blvd, as 8th Avenue, it became divided and then swung south on a hillside to where it became 6th Avenue. At least, up until a few years ago, that segment where 8th swung over to 6th was still in existence, although no longer connected to the Freeway. [Author: Still true.]

Before 1975, US 6 continued west into Utah from Mack on its own rather than using I-70, so there was a "Spur US 6" connection between I-70 and US 6 at Mack. In 1975, this route west of Mack was eliminated and US 6 moved onto I-70, so the spur became part of the main route.

By 1992, SH 93 was rerouted out of downtown Golden to the west to meet up with US 6/SH 58, and the partial interchange there, with a flyover from WB 6 over SH 58 into Clear Creek Canyon, was eliminated.

The US 6 West Parachute interchange (Exit 72) opened in November 2012. Previously there was just an overpass taking US 6 over I-70 without ramps.

Related Sites:


Last updated 9 March 2014