Gross Reservoir in Colorado

by  guest-paddler

A self-supported trip created by guest-paddler

Trip Overview

Exciting news from Gross Reservoir, Colorado. My name is Rick Lewis, as Recreation Manager here at Gross Reservoir. I am pleased to announce that Gross Reservoir, operated by Denver Water, will open for cartop boating on Saturday May 28 at Sunrise.

This hidden Gem lies in the foothills above Boulder, Colorado on the South Boulder Creek Drainage as it cuts its way through fantastic Granite rock outcroppings sculpted by Glaciers. Completed in 1954 as a water storage facility by Denver Water, the reservoir was off limits to paddlers, but the recent approval for a hydroelectric generating license by the Federal Government has opened the water to boating.

Cartop boats, including kayaks, canoes and rowboats, multi-chamber inflatables that can be carried to the water will be allowed. Not permitted will be sailing craft, sailboards, gas or electric motors, belly boats or trailered craft. The paddling season will extend from Memorial Day through September 30.

The setting here at Gross Reservoir is fantastic, dominated by the snow-covered peaks of the Continental Divide, pine-covered slopes are accented by polished Granite outcroppings. With over fourteen miles of shoreline and several long arms the scenery is splendid. At over three hundred feet in depth and an altitude of 7500 feet, Gross is a cold water lake providing excellent trout fishing.

Paddling here can prove challenging, especially when strong winds race downslope off the Divide or thunderstorms form quickly. The glassy surface can be transformed to whitecaps and gusts of wind exceeding 60 miles per hour within minutes. That combined with the very cold water poses risks for the unprepared, always wear your life vest and keep an eye on the weather.

As Recreation Manager I will be on site providing land and water patrols to aid the public and provide information and safety. The Reservoir is open from sunrise to sunset. Gross Reservoir is in a remote location with limited facilities, so come prepared with adequate supplies and clothing to meet the extremes in weather which can range from 85 degree heat to an icy hailstorm.

We here at Denver Water are excited and proud to provide an excellent paddling opportunity and to maintain high safety standards.


Accommodations and paddling shops with rentals are available in Golden and Boulder. Restrooms and picnic facilities, on site, with primitive camping on West Bank, gas, lodging and restaurants within 6 miles of reservoir in Coal Creek. Emergency Call Boxes on site, very limited cell phone coverage.


None currently required.


Gross Reservoir lies in the foothills above Boulder Colorado. From Boulder take Baseline Rd. to Flagstaff Rd., continue climbing for 9 miles to Gross Dam Rd. on left, follow signs to South Side and Osprey Boat Launch Site.

From Denver, take Hwy. 93 north from Golden to Hwy. 72 West, Coal Creek Canyon, climb 7 miles to Crescent Park Rd. on right then 1 mile to Gross Dam Rd. to right, follow signs to Osprey Boat Launch Site.


Questions or comments can be directed to Rick Lewis, Denver Water Recreation Site Coordinator.

Phone: (303)634-3641

E-Mail: [email protected]

Mail: Denver Water 1600 W. 12th Ave. Denver Co. 80204-3412 Mail Code 731

Further information about Gross Reservoir and other recreational opportunities at Denver Water Facilities at our Website -


USFS Arapaho Roosevelt NF users map. Topozone or Mapquest web sites.

Trip Details

  • Sport/Activity: Kayaking, Canoeing
  • Skill Level: Intermediate
  • Water Type: Flat/Sheltered Water

Trip Location