Leanin' Tree Museum of Western Art

Boulder Reservoir is located in the northern part of Boulder, Colorado. It stores water for the Northern Colorado Water Conservancy District — also called Northern Water — and for the City of Boulder. The reservoir is the centerpiece of the Boulder Reservoir Regional Park, which is managed by the City of Boulder's Department of Parks and Recreation. The reservoir receives most of its water from Colorado's Western Slope through the Alva B. Adams Tunnel and the Boulder Feeder Canal, both part of the Colorado-Big Thompson Project. Some of the stored water is used as part of Boulder's municipal water supply and some is used for agricultural purposes in Boulder and Weld counties.

Boulder County Poor Farm is the site of a poor farm in Boulder County, Colorado, where long-term care for the county's indigent was provided from 1902 to 1918. The site was operating as a farm from 1897, and many of the original farm buildings are still present, including a main house built in Queen Anne style. It was listed on the National Register of Historic Places in 2011. Starting in 1875, Boulder County leased a series of properties to serve as the county poorhouse. In 1902, the 120-acre (49 ha) farm on today's 63rd Street was purchased to house the institution; many modifications were made to the farm house, including the construction of a two-story dormitory annex. By 1918, a larger building was needed, and the institution was moved to another location. The farm was sold and returned to private operation.

Fourmile Canyon Creek or Four Mile Canyon Creek is a tributary of Boulder Creek. Its source is northwest of Boulder, Colorado and flows through the northern part of the city for part of its length. It should not be confused with a similarly named stream that runs through Fourmile Canyon west of Boulder, which was the site of a major wildfire in 2010. This stream rises west of the old mining settlement of Sunshine. It runs eastward through the foothills of the Front Range in Boulder County, Colorado, south of Left Hand Canyon and north of Sunshine Canyon. The creek exits the mountains to the plains near Lee Hill Road in northern Boulder, then flows east an additional 5 mi (8.0 km) through the plains to its confluence with Boulder Creek near Valmont. This stream is home to Boulder Open Space land, a trailhead, and the Anne U. White Trail. Although Fourmile Canyon Creek is a seasonal intermittent stream in the plains, it is also the target of flash flood prevention efforts.

Boulder Municipal Airport (IATA: WBU, ICAO: KBDU, FAA LID: BDU) is a public airport located 3 miles (4.8 km) northeast of the central business district of Boulder, a city in Boulder County, Colorado, United States. It is owned by the City of Boulder and used almost exclusively for general aviation. Its location in the foothills of the Rockies east of the continental divide gives excellent conditions for soaring, and there is extensive gliding activity. It is the base of the Soaring Society of Boulder. Most U.S. airports use the same three-letter location identifier for the FAA and IATA, but Boulder Municipal is BDU (formerly 1V5) to the FAA and WBU to the IATA (which assigned BDU to Bardufoss Airport in Bardufoss, Norway).

South Boulder Creek is a tributary of Boulder Creek in central Colorado in the United States. Its source is near Rogers Pass on the Continental Divide. The stream flows to a confluence with Boulder Creek in northeast Boulder. Gross Dam is located on South Boulder Creek, approximately 4+1⁄2 miles west of Eldorado Springs, Colorado.

Valmont is an unincorporated community and a census-designated place (CDP) located in and governed by Boulder County, Colorado, United States. The CDP is a part of the Boulder, CO Metropolitan Statistical Area. The population of the Valmont CDP was 59 at the United States Census 2010. The Boulder post office (Zip Code 80301) serves the area.

Walden Ponds Wildlife Habitat is a 102-acre (41 ha) Boulder County, Colorado park. It was reclaimed between 1974 and the 1990s from an open-pit gravel mine on the site, and is named after Walden "Wally" Toevs, the Boulder County Commissioner who spearheaded the plan to convert the gravel pits into a wildlife habitat.After the mining ceased and the property had been stripped 15 feet (4.6 m) down to bedrock, all that was left were open pits and puddles of ground water.The park has several ponds and marshlands, hiking trails, picnic facilities, restrooms, and fishing. It claims to be one of the best bird-watching areas in Boulder County.

The McKenzie Well (also known as McKenzie #1) is an oil well site in Boulder, Colorado. The Boulder Oil Field was discovered on this site in 1901, making it the oldest oil-producing site in the entire Denver Basin, and one of the oldest in the western United States. The first producing well on the site was drilled in 1902. Peak production at 85,000 barrels was reached in 1909.A modern well (built in the 1960s) sits on the site of the original discovery; nothing remains of the original machinery.The McKenzie Well site is listed on the National Register of Historic Places and the Colorado State Register of Historic Properties.

Gunbarrel is an unincorporated community and a census-designated place (CDP) located in and governed by Boulder County, Colorado, United States. The CDP is a part of the Boulder, CO Metropolitan Statistical Area. The population of the Gunbarrel CDP was 9,263 at the United States Census 2010. The Boulder post office (Zip Code 80301) and Niwot post office (Zip Code 80503) serve the area.

Climbing is a major US-based rock climbing magazine first published in 1970. In 2007, it was bought by Skram Media, the publisher of Urban Climber Magazine. The headquarters of the magazine is in Boulder, Colorado. It is published nine times a year. Climbing was purchased by Outside in 2021.

The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences.

The Space Science Institute (SSI) in Boulder, Colorado, is a nonprofit, public-benefit corporation formed in 1992. Its purpose is to create and maintain an environment where scientific research and education programs can flourish in an integrated fashion. SSI is among the four non-profit institutes in the US cited in a 2007 report by Nature, including Southwest Research Institute, Planetary Science Institute, and Eureka Scientific, which manage federal grants for non-tenure-track astronomers.