Tucked neatly into the foothills past Flagstaff Mountain, you’ll be amazed you haven’t been to this beautiful water body since you’ve been living in Boulder. Gross Reservoir has 10.9 miles of shoreline and it’s totally not gross.

Driving up the backside from Coal Creek Canyon we came around a bend, the reservoir was visible sitting under hills and mountains. Clouds hung overhead, and the dark water reflected the surrounding hills. It was pretty epic looking!

We took turns going out on a stand up paddle board on the still water. Eventually the sun came out and it started to feel like a real beach, complete with beautiful mountain views.

The site is owned by Denver Water and is great for non-motorized boating and all sorts of shoreline recreation. Be aware that rangers patrol the area regularly and by boat, so it’s best to read and follow the rules posted at the trailhead (as with any park!). Their website gives a nice summary of the place.

Directions: Head west on Baseline, which turns into Flagstaff Road just past Chautauqua. Continue all the way up to mountain and pass by Walker Ranch, about 12 miles from the start of Flagstaff.  You’ll get to the North side shore first but you can easily head further down to the South Side where you can access the giant dam.

Unfortunately, swimming is not allowed. Swimming spots around Boulder are not plentiful and I personally don’t like the thought of swimming in “The Rez” which gets closed all the time for e.Coli and other dog poop problems. Maybe they should call that reservoir gross instead.

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