Highway 119 begins at a signalized T intersection with
U.S. Highway 6 in
Clear Creek Canyon between
Golden and
Idaho Springs. It then heads north, alongside North Clear Creek, to the gambling town of
Black Hawk, Colorado; this section of the road carries heavy traffic to the casinos of Black Hawk and
Central City and experiences many accidents. mountains as seen from northbound State Highway 119, between Black Hawk and Rollinsville It continues north from Black Hawk as the
Peak to Peak Scenic and Historic Byway, skirting the western edge of
Golden Gate Canyon State Park where it intersects
State Highway 46. It continues north through the village of Mid Gilpin to
Rollinsville, where it crosses over
South Boulder Creek and the tracks of the
Union Pacific Railroad, on its way from
Denver to the
Moffat Tunnel. East Portal Road in Rollinsville provides access to the east portal of the railroad tunnel, and to the Moffat Road historic railroad grade across
Rollins Pass. SH 119 continues northward, intersecting
State Highway 72 with which it will be concurrent to
Nederland. It provides access to the
Eldora Mountain Resort ski area, about west of Nederland. In Nederland, SH 119 and SH 72 diverge at a
roundabout intersection where SH 72 takes the Peak to Peak Highway designation with it to the north, and Route 119 turns to the east. Leaving Nederland, SH 119 passes along the northern shore of
Barker Meadow Reservoir and enters the scenic Boulder Canyon, alongside
Boulder Creek. In the canyon, the road experiences grades of up to 10%, which can be dangerous for heavy trucks heading downhill, as it does not have a
runaway truck ramp. The walls of the canyon are popular for
rock climbing, and the scenic
Boulder Falls is an easy walk from the highway. At the mouth of the canyon, SH 119 suddenly enters
Boulder as Canyon Boulevard, intersecting
State Highway 93 at Broadway, and turning north on 28th Street where it begins concurrency with
U.S. Highway 36 and with unsigned
State Highway 7. This busy section of State 119 and US 36 on 28th Street serves Boulder's main shopping area. The overlap with US 36 ends at the northern edge of Boulder where US 36 continues north to
Rocky Mountain National Park, and SH 119 turns east becoming Diagonal Highway. At an intersection with
State Highway 157, SH 119 bends northeast, paralleling the tracks of the
Burlington Northern Santa Fe Railway, and becomes an
expressway with a very wide median, possibly intended to accommodate a future
freeway. At
Niwot it passes a very large facility for the
IBM Corporation at an intersection with
State Highway 52. The Diagonal Highway expressway ends in
Longmont, as SH 119 becomes Ken Pratt Blvd. and intersects
U.S. Highway 287. East of US 287 in Longmont, a new expressway carries SH 119 directly to its northeastern terminus at a
diamond interchange at
Interstate 25 exit 240. ==History==