Baseline Road (Colorado)
Baseline Road is a long east-west road in Boulder, Colorado. It starts at Flagstaff Mountain in Boulder Mountain Parks and ends at 16800 Watkins Road, about 6 miles east of Lochbuie on the Adams–Weld county line. The road is about 38 miles long, all within the Denver metro area. It runs almost exactly along the 40th parallel north, a line that was used as a baseline for land surveys in the area.
Historically, after Colorado Territory formed in 1861, the 40th parallel became the main survey baseline. Baseline Road follows that line and has different names in different counties: Baseline Road in Boulder County and Broomfield, 168th Avenue in Adams County, and County Line Road or Weld County Road 2 in Weld County. A 7-mile section from Lafayette to Broomfield is part of State Highway 7.
Route highlights: The road descends from Flagstaff Mountain into Boulder, passing near the Chautauqua and the CU Law School, crossing Broadway (State Highway 93), 28th Street, and Foothills Parkway. East of 55th Street it continues toward Cherryvale Road, then heads into Lafayette, where it intersects US 287. It then crosses into Erie and forms part of the Weld–Broomfield boundary for a couple miles, runs through northern Broomfield, and near Thornton. The road then marks the Adams–Broomfield boundary near York Street and continues as the Adams–Weld boundary for the rest of its length, passing through rural areas toward Brighton, Lochbuie, and finally ending at Watkins Road after crossing I-76.
This page was last edited on 2 February 2026, at 17:20 (CET).