Colorado State Highway 121

State Highway 121 (SH 121) also known as Wadsworth Boulevard across its entire length, is a 30.425 mile (48.96 km) long state highway in the U.S. state of Colorado. SH 121's southern terminus is at Waterton Road near Littleton, and the northern terminus is at U.S. Route 287 (US 287) in Broomfield.

State Highway 121
Wadsworth Blvd
Map of north central Colorado with SH 121 highlighted in red
Route information
Maintained by CDOT
Length	30.425 mi[1] (48.964 km)
Major junctions
South end	Lockheed Martin Space Systems near Roxborough Park
Major intersections	SH 470 near Lakewood US 285 in Lakewood US 6 in Lakewood US 40 / I-70 BL in Lakewood I-70 / I-76 in Arvada US 36 in Broomfield
North end	US 287 in Broomfield
Location
Country	United States
State	Colorado
Counties	Jefferson, Denver, Broomfield
Highway system
Colorado State Highway System Interstate US State Scenic
← SH 120 → SH 125

Route description

End of SH 121 just before Waterton Road

The route, also known as Wadsworth Boulevard, Wadsworth Bypass, and Wadsworth Parkway, starts at a junction with Waterton Road in unincorporated Jefferson County (near Littleton and at the entrance to the main plant of Lockheed Martin Space Systems) and ends at the junction of U.S. Route 36, U.S. Route 287, and State Highway 128 in Broomfield at a trumpet interchange. State Highway 121 passes through portions of southwest Denver County.

History

Wadsworth Boulevard (Colorado Highway 121) at Bowles Ave. in Littleton, Colorado.

The name Wadsworth comes from Benjamin Franklin Wadsworth, one of the founders and first postmaster of Arvada. In northwest Arvada, Wadsworth Boulevard passes over Hackberry Hill at the site where a landmark hackberry tree, for which the hill was named, stood before it was cut down to make room for the highway in 1937.^[2]

Major intersections

County	Location	mi	km	Destinations	Notes
Jefferson	​	0.00	0.00	Lockheed Martin Space Systems entrance	Southern terminus
	​	4.41	7.10	SH 470 (C-470)	Interchange; SH 470 exit 13
Denver	No major junctions
Jefferson	Lakewood	7.49	12.05	US 285 (Hampden Avenue)	Interchange
		9.06	14.58	SH 8 west (Morrison Road)	Eastern terminus of SH-8
		12.44	20.02	US 6 (Sixth Avenue)	Interchange
		13.59	21.87	US 40 / I-70 BL (Colfax Avenue)
	Arvada	16.79	27.02	I-70 / I-76 east – Denver, Fort Morgan, Grand Junction	I-76 exit 1A; I-70 exit 269A
City and County of Broomfield		25.82	41.55	SH 128 (Interlocken Loop)
		26.02	41.88	US 36 – Denver, Boulder	Interchange
		26.42	42.52	US 287	Interchange; northern terminus; road continues north as US 287
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       Incomplete access