Northwest of Carter Lake

This quiet, 47-acre reservoir is surrounded by 200 acres of public lands. It's a popular spot for fishing, picnicking, and family camping. Swimming and boating are not allowed here, but nearby Carter Lake offers both!

As part of the Colorado-Big Thompson Project to divert water from the west slope to the east slope for drinking water, irrigation, and hydropower generation, the reservoir is jointly operated by the Bureau of Reclamation and the Northern Colorado Water Conservancy District who manage water levels for irrigation, municipal, and industry use. Larimer County manages recreation.

Flatiron Reservoir requires entrance and camping permits, and is open year round. At 5,470 feet in elevation, it is a few miles northwest of Carter Lake, southwest of Loveland, Colorado, and northwest of Berthoud, Colorado.



Accessible Activities
Drinking Water
Permit Required
Picnic Area
Reservable Pavilions



From Denver:

  1. Take I-25 North to the Berthoud Exit (Exit 250).
  2. Turn left (west) onto Highway 56 and continue for 9 1/2 miles. (You will pass through the town of Berthoud.)
  3. Watch for the Carter Lake road sign after a sharp curve to the north (right).
  4. Turn left (west) onto County Road 8E and continue for 3 miles.
  5. Stop at the entrance station to purchase Park Entrance Permits, Follow County Road 8E west to the intersection about halfway up the hill. A sign will direct you to continue straight to the South Shore Campground or to turn right to Carter Knolls Campground, the swim beach, Big Thompson Campground, Carter Lake Marina, Eagle Campground, Lowell's Campground and North Pines Campground. The Natural Resources Department is located about 2 miles north of Carter Lake at 1800 South County Road 31.

From Longmont or Boulder:

  1. Take U.S. Highway 287 north to County Road 56 west of Berthoud.
  2. Turn left (west) onto County Road 56.

    Follow direction from # 3 above

From Loveland:

  1. Drive west of Loveland on U.S. Highway 34 to mile marker #85. Watch for the "Carter Lake" sign.
  2. Turn left (south) onto County Road 29. Go 2 miles and turn right (west) onto County Road 18E. Go west another 2 miles. Watch for the park signs.
  3. At County Road 31 turn left and stop to purchase park entrance permits at the entrance station on your right or at The Natural Resources Department. Continue south on County Road 31 another 2 miles to Carter Lake, campgrounds, marina, and swim beach.

From Fort Collins:

  1. Take Taft Hill Road south from Fort Collins to U.S. Highway 34 (Eisenhower) in Loveland and turn right (west).

    Follow directions from Loveland above.


BE BEAR AWARE: Avoid attracting bears to your campsite

  • Never leave food, cooler or trash unattended. Any food, coolers or trash left out may be confiscated.
  • Properly store your trash, food, beverages and toiletries in a locked hard-sided container constructed of rigid material. Keep anything with a scent in your vehicle or a bear-proof container. Put trash in dumpsters located at each campground.
  • Keep a clean tent. Don't bring anything with an odor into your tent. Don't sleep in the clothes you cooked in; store them in your vehicle.
  • Never intentionally feed a bear.


Self-serve permit stations are NOT available at this reservoir. Permits can be purchased at the north or south entrance gatehouses for Carter Lake, the administrative office east of Flatiron Reservoir, and at the north shore marina store at Carter Lake.

Flatiron Reservoir water elevation is 5,417 feet empty and 5,480 feet full
Water Level Data courtesy U.S. Bureau of Reclamation