Gross Reservoir

Background

Named for Denver Water former Chief Engineer Dwight D. Gross, the reservoir was completed in 1954. It serves as a combination storage and regulating facility for water that flows under the Continental Divide through the Moffat Tunnel.

Standing 340 feet above the South Boulder Creek streambed, Gross Dam contains some 627,559 cubic yards of concrete. Gross Reservoir has a surface area of 440 acres and 10.9 miles of shoreline.

Directions

From Denver metro area:

• Take Highway 93 north from Golden to Highway 72
• Turn left (west) on Highway 72 toward Pinecliffe to County Road 77/Gross Dam Road
• Gross Dam Road will take you to both the north and south access points

To reach the dam from Boulder:

• Take Flagstaff Road west until it turns into eastern Gross Dam Road

Seasonal Information

Open year round

Boating season is from the Memorial Day weekend through September 30

Kokanee snagging runs from Sept. 1 – Jan. 31

West site U.S. Forest Service closes from late fall to early spring: check with the U.S. Forest Service Boulder district for specific closure dates

Operating Hours

Half hour before sunrise to half hour after sunset

Recreation Opportunities

Overview of available activities

fishing	Cold water fishing; stocked by Colorado Division of Wildlife.  Also see Stocking Reports.
ice fishing	Ice fishing when conditions permit. Denver Water does not monitor ice conditions and those entering the ice should be aware of changing ice conditions and proceed at their own risk. Check with State Parks.
canoeing kayaking	Boating is allowed (car-top non-motorized only) from Memorial Day through the end of September. No trailer-hitched boats are allowed. Kayak access to the river below Gross Reservoir is available at the parking area below the dam. See map.
picnicking	The east side developed areas are for day use only. Sheltered tables also available.
camping	Limited access. High clearance vehicles required. West side managed by Roosevelt National Forest. Area has seasonal closure; check with Boulder District.
hiking	Hiking is permitted from North Shore picnic area (trailhead to Rocky Point), South Side Dam, Miramonte picnic area, and Osprey Point (trailhead), to South Boulder Creek inlet.

Note: Water contact sports such as swimming, wading, scuba diving or other water activities are prohibited.

Other rules and regulations.