This stretch of creek is a Class V kayak course, meaning dangerous or deadly rapids exist. Wading above waterfalls, constrictions, or kayak portages is exceptionally dangerous. A few wide sections offer crossings when flows are below 150 cfs.
Hiking the tailwater below Gross Reservoir gets one away from the car on a foot path. Steep canyon ...
From Boulder drive West on Baseline Road, which becomes Flagstaff Mountain Road. Turn Left onto a dirt road at the Gross Reservoir North Shore parking area (Gross Dam Road). Public parking is in a small lot on the North side of South Boulder Creek. For a longer hike in, parking is available at the Walker Ranch Trailhead, off of Flagstaff Mountain Road.
Eldorado Canyon State Park:
From Boulder drive South on Hwy 93 toward Eldorado Springs and turn West onto Rd 170 (Eldorado Springs Drive). State Park entry fee or park pass is required.