Arapaho National Recreation Area

The Colorado–Big Thompson Project (abbreviated C-BT) is a federal water diversion project in Colorado designed to collect West Slope mountain water from the headwaters of the Colorado River and divert it to Colorado's Front Range and plains. In Colorado, approximately 80% of the state's precipitation falls on the West Slope, in the Rocky Mountains, while around 80% of the state's growing population lives along the eastern slope, between the cities of Fort Collins and Pueblo. Eleven reservoirs, about 18 dams and dikes, the Alva B. Adams Tunnel under the Continental Divide, as well as six power plants, make up the project. The C-BT is owned and primarily managed by the U.S. Bureau of Reclamation's Eastern Colorado Area Office under its Great Plains Region.

Lake Granby is the third largest body of water in Colorado. It was created by the erection of Granby Dam, completed in 1950, as part of the Bureau of Reclamation's Colorado-Big Thompson Project. Water from Lake Granby is pumped via the Farr Pump plant though a pipeline that empties into a canal connected to Shadow Mountain Reservoir. The Bureau of Reclamation owns Farr Pump plant while Northern Water operates it. On its own, Lake Granby contains approximately 40 miles (64 km) of shoreline. The lake is popular with anglers and is continually stocked with rainbow trout and kokanee salmon. The Lake is also home to the Lake Granby Yacht Club. At 8,280 feet (2,520 m), LGYC is one of the highest-elevation yacht clubs in the world, slightly beating out Grand Lake Yacht Club on nearby Grand Lake.

Granby Dam (National ID # CO01656) is an earthfill dam that dams the Colorado River 5.5 miles (8.9 km) northeast of Granby, Colorado in Grand County, Colorado. This 298-foot (91 m)-tall dam was constructed between 1941 and 1950 and has a drainage area of 311 square miles (810 km2). The Granby Dam's reservoir is known as Lake Granby, the largest reservoir component of the Colorado-Big Thompson Project. Lake Granby stores Colorado River water that is diverted under the Continental Divide for agriculture and municipal use within north-eastern Colorado including the cities of Boulder, Fort Collins, Loveland, and Greeley. In addition to the waters of the Colorado, water from Willow Creek just below the dam is pumped up 175 feet (53 m) to Lake Granby. Water from Lake Granby is pumped 125 feet (38 m) higher by the Granby Pumping Plant to the Granby Pump Canal, which extents 1.8 miles (2.9 km) to Shadow Mountain Lake, from which water is diverted through the Alva B. Adams Tunnel to the East Slope.This damsite does not generate any power directly; power is generated at other locations in the Colorado-Big Thompson Project.

Willow Creek is a tributary of the Colorado River, approximately 35 miles (56 km) long, in north central Colorado in the United States. It rises in northwestern Grand County, in the Arapaho National Forest south of Willow Creek Pass at the continental divide. It flows southeast through Willow Creek Reservoir and joins the Colorado three miles northeast of Granby.

Middle Park (elev. 8,000 ft or 2,400 m) is a high basin in the Rocky Mountains of north-central Colorado in the United States. It is located in Grand County, on the southwest slope of Rocky Mountain National Park, approximately 50 miles (80 km) west of (and across the continental divide from) Boulder.

Willow Creek Dam (National ID # CO01670) is a dam in Grand County, Colorado. The earthen dam was constructed between 1951 and 1953 by the United States Bureau of Reclamation, with a height of 127 feet (39 m), and a length of 1,100 feet (340 m) at its crest. It impounds Willow Creek for irrigation water storage and hydroelectric power, part of the Bureau's larger Colorado-Big Thompson Project. The dam is owned by the Bureau and operated by the local Northern Colorado Water Conservancy District. The reservoir it creates, Willow Creek Reservoir, has a normal water surface of 303 acres (123 ha), and has a maximum capacity of 11,177 acre-feet (13,787,000 m3). Recreation includes camping and fishing (for brown trout, rainbow trout, and salmon).

The Town of Granby is the Statutory Town that is the most populous municipality in Grand County, Colorado, United States. The town population was 2,079 at the 2020 United States Census. Granby is situated along U.S. Highway 40 in the Middle Park basin, and it is about 85 miles (137 km) northwest of Denver and 14 miles (23 km) southwest of Rocky Mountain National Park.

Granby station is a train station in Granby, Colorado. It is served by Amtrak's California Zephyr, which runs once daily between Chicago and Emeryville, California, in the San Francisco Bay Area. Despite its antiquated appearance and structure (the station is made of wood), the station was built in 1987. Granby is proposed as a station to use for access of the Rocky Mountain National Park by train. However, while the train ride (from the Denver side) provides impressive views, the station itself lies 16 miles (26 km) from the park, without public transportation connections.

The Fraser River is a tributary of the Colorado River, approximately 32.5 miles (52.3 km) long, in north central Colorado in the United States. It drains a large portion of the Middle Park basin in Grand County in the Rocky Mountains west of Boulder and southwest of Rocky Mountain National Park. It rises at the continental divide on the north side of Berthoud Pass in the Arapaho National Forest. It flows NNW past Winter Park, Fraser, and Tabernash, and joins the Colorado River from the south two miles west of Granby.