Boulder is a home rule city that is the county seat and most populous municipality of Boulder County, Colorado. Boulder is the principal city of the Boulder, CO Metropolitan Statistical Area and is part of the Front Range Urban Corridor. The city had a total area of 17,514 acres (70.877 km2) including 664 acres (2.689 km2) of water.
Boulder lies at the base of the Rocky Mountains. Boulder is 25 miles (40 km) northwest of the Colorado state capital of Denver. It borders Pine Brook Hill, Valmont, Louisville, Eldorado Springs, and Seven Hills. Major highways serving the city include U.S. Route 36, Colorado State Highway 119, Colorado State Highway 7 and Colorado State Highway 93. Boulder is situated in the Boulder Valley, where the Rocky Mountains meet the Great Plains. West of the city are the Flatirons, sandstone slabs jutting up from the foothills. The Flatirons are a widely recognized symbol of Boulder.
Boulder Creek is the primary source of water in Boulder. Prior to the city’s founding, the creek was named for large granite boulders that cascaded into it over eons. Boulder Creek, which has significant flow, is primarily derived from snowmelt and minor springs west of the city. The creek is a tributary of the South Platte River.
SH 7 emerges east from Foothills Parkway and ends at US 287 with Lafayette. US 36 runs northwest and southeast and becomes 28th Street within Boulder. SH 119 runs west and northeast. SH 93 emerges southeast from SH 119 and ends and SH 72 to the south.
Boulder is home of the main campus of the University of Colorado, the state’s largest university. Other colleges within Boulder are Naropa University and Auguste Escoffier School of Culinary Arts. Boulder Municipal Airport is located 3 miles (4.8 km) from the center of Boulder, while Denver International Airport is located 45 miles (72 km) southeast of Boulder.
Boulder is surrounded by thousands of acres of recreational open space, conservation easements, and nature preserves including Gateway Park Fun Center, Foothills Community Park, Valmont Dog Park, North Boulder Park, Gerald Stazio Softball Fields, Flatirons Golf Course and Scott Carpenter Park. The public has access to nearly 60%, or 35,584 acres (144.00 km2), of the 61,529 acres (249.00 km2) of open space.
The Regional Transportation District (RTD) operates a comprehensive bus system in Boulder. With departures, every ten minutes during peak hours, Monday-Friday, the HOP, SKIP, JUMP, Bound, DASH, and Stampede routes run throughout the city and connect to nearby communities. In addition, there are routes 204, 205, 206, 208 and 209 that depart every 15 to 30 minutes. There are also regional routes serving nearby cities such as Longmont (BOLT, J), Golden (GS), and Denver (Flatiron Flyer, a bus rapid transit route), as well as Denver International Airport (AB).