Colorado State Highway 121

State Highway 121
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

State Highway 121 (SH 121) 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.