S Boulder Creek Place Holder

South Boulder Creek (Lite Report)

Difficulty Beginner/Intermediate
Ideal Days To Fish NA

Weekly Report

Report DateSept. 2, 2022

Note: This report is a part of the FlyCast Lite reporting program and is updated seasonally or in the event of substantial changes that alter fly fishing tactics. FlyCast Lite reports are intended to give anglers a high level overview on seasonal conditions and general fishing tactics.

South Boulder Creek, below Gross Reservoir, is fishing well and a great place to get your dry fly fix while not spending the entire day in the car. Flows are at a healthy level and trout are feeding opportunistically throughout the day. Hatch activity has been consistent with midges, PMDs, drakes and caddis all making regular appearances. Otherwise, terrestrial activity has been picking up and trout are actively seeking an easy meal along the banks. In general, but especially this time of year, a dry dropper or hopper dropper is our go to mode of fishing. If you find yourself immersed in a hatch, go with a dry to an emerger and hit the slower riffles and seams. Otherwise, hit the banks hard with a hopper dropper. As far as droppers go, anything buggy should do the trick. However, Pat’s Rubber Legs, Guide’s Choice Hare’s Ears, Flashback PTs, Copper Johns and Brassies have been a few of our favorites. That said, you can’t go wrong with something more imitative in the midge, baetis, stonefly or caddis variety. Additionally, after it rains, a San Juan Worm, or even a smaller streamer, have been effective as well.

Recommended Flies

River Flow

Flow Region

Detailed River Info


South Boulder Creek is one of the more beautiful places to fish within an hour of Denver. It originates in the Indian Peaks Wilderness and makes its way down to the Gross Reservoir. Below the reservoir is the tailwater, which flows through the Walker Ranch Open Space. While the creek above the reservoir presents some decent fishing and offers a number of public access points, for the sake of this report, we’ll be focused on the section below the Gross Reservoir. The tailwater is home to a variety of trout species. However, it is most known for its brown and rainbow trout. This section is one of the more popular stretches and can be fished year-round. That being said, much of the river freezes over in the winter leaving fewer fishable locations. The creek itself meanders through a beautiful canyon and is detached from the road. So if you enjoy some peace and quiet as well as a short hike, South Boulder Creek is for you.


South Boulder Creek is fairly forgiving and a viable option for anglers of all skill sets. Given that it is a creek, you can expect comparatively narrow water as well as large boulders that create some amazing pocket water. While flows in the spring, late summer and fall are fairly stable, this stretch is particularly prone to run-off from feeder creeks. That said, you can still manage to catch fish during this time. The summer and fall offer prime dry fly fishing conditions as there are a variety of hatches in the caddis, PMD, BWO, midges and terrestrial variety. You can’t go wrong with the dry dropper set-up. Elk Hair Caddis, Amy’s Ant’s and Chubby Chernobyls all make for great point flies. Otherwise, the nymph rig with searchers, attractors or imitative nymphs will treat you well all year. Regardless of how you fish, you’re going to want to focus on the banks and outer seams to start, but don’t discount the shallow riffles and runs, pools or pocket water.

River Access

To access South Boulder Creek below Gross Reservoir, take Highway 93 (north from Golden or South from Boulder) until you reach Highway 72. From here, follow the highway until you reach the Gross Reservoir turnoff (Crescent Park Drive). After about 4.5 miles you’ll make a right on Gross Dam Road to which you’ll find parking via the Walker Ranch Open Space.