Boulder Reservoir

Boulder Reservoir quick facts

Boulder Reservoir at a glance

The Boulder Reservoir is a 700-acre, multi-use recreation and water-storage facility owned and managed by the City of Boulder. On a summer day it's Boulder's beach: people swim off the sandy swim area, paddle boards and kayaks fan out across the water, families picnic and grill, and runners and cyclists loop the shoreline. It's a different feel from the foothill trails, flat, open, and social.

Boulder Reservoir hours and entrance fee

A daily entry fee is charged April 1 through October 31, and everyone entering pays, including runners, walkers, and cyclists. In peak season (late May through early September) the day rate is $12 per person, $20 for a car of two, or $30 for a carload of three to five, with a $5 rate if you run, walk, or cycle in. In the shoulder weeks it drops to $5 per person or $10 per carload, and from November 1 through March 31 there's no access fee at all. Gate hours run roughly 6 a.m. to 8 p.m. in peak summer and shrink to about 10 a.m. to 3 p.m. in winter, so check the city's hours page before you drive out.

Boulder Reservoir parking

Parking is inside the entrance at 5565 51st Street, in large paved lots. On hot summer weekends the lots near the swim beach fill up, so come early or late in the day. Your entry fee covers the vehicle and its occupants under the carload rates above.

Swimming and the swim beach

Swimming is allowed only in the designated swim area, and only while lifeguards are on duty. The swim beach is generally open 10 a.m. to 6 p.m. daily from Memorial Day weekend through Labor Day. Swimming anywhere outside the marked area is prohibited, and the beach can close temporarily for algae blooms, so it's worth checking the day's status.

Paddling, SUP, and boat rentals

Every watercraft needs a current City of Boulder Boulder Reservoir permit to launch, and that includes stand-up paddleboards, kayaks, canoes, and inflatables, not just motorboats. If you don't own a board, Rocky Mountain Paddleboard rents on site. Note the reservoir runs no-wake and limited-wake hours through the week to keep paddlers and swimmers safe alongside motorboats.

The shoreline loop and dogs

A wide, mostly flat path and service road loop the water, which makes for an easy run or walk of roughly five miles with almost no climbing. Dogs, though, are the catch: they're prohibited through the gates and along the south shoreline from May 15 through Labor Day. In the off-season when dogs are allowed, they have to be leashed, and the OSMP Voice and Sight tag that works on the foothill trails doesn't apply here. If you're hiking with a dog in summer, one of the foothill trails is the better call.

Best season and time to go

For swimming and paddling, come between late May and Labor Day, early on weekends to beat the crowds and the parking crunch. For a quiet walk or run with no fee, the off-season from November through March is the reservoir's best-kept secret: cold and windy, but empty and free.

Nearby trails and guides

• All hikes in Boulder: the full hiking hub, sorted by difficulty.
• Mount Sanitas: a steep foothill climb if you'd rather earn a view than hit the beach.
• Walker Ranch: a rugged loop for a bigger day out.

Recommended nearby

A few local spots we'd point a reservoir day toward.

Boulder Reservoir FAQ

Sources

Facts on this page are drawn from these authoritative sources:

• City of Boulder: Boulder Reservoir
• City of Boulder: Reservoir Facility Fees
• City of Boulder: Reservoir Facility Hours
• City of Boulder: Boulder Reservoir General Rules and FAQs