Colorado Fly Fishing 3 min read

DIY Guide to Fly Fishing South Boulder Creek in Colorado

Ken Sperry

Posted by Ken Sperry

May 24, 2024

south boulder creek in eldorado canyson state park in colorado

Nestled amidst the foothills of the Colorado Front Range, South Boulder Creek offers some fantastic fishing for anglers who don’t mind doing a little driving from point to point or doing a little hiking.The headwaters of South Boulder Creek form up west of Rollinsville, CO and from there follow the railroad tracks east all the way through Moffat Tunnel to the Gross Reservoir.

About South Boulder Creek

Fly fishing South Boulder Creek near Walk Ranch in Colorado

Below the reservoir, all the way to Eldorado Canyon lies the South Boulder Creek tailwater.

Along the way, you will see some of the most beautiful mountain meadow and high altitude pasture land in all of the United States.

The main attractions for fly fishing South Boulder Creek are brown trout, but there are plenty of rainbows and the occasional cutthroat and brook trout to be had here, too. 

The stream itself contains massive eponymous boulders from which the creek derives its name, and each forms a deep pool around itself where crafty trout like to hide. 

The water is pretty much crystal clear during peak season, so you will want to make sure you approach quietly and carefully so as not to scare off your catch of the day.

South Boulder Creek Fly Fishing Map

map of fishing access spots on South Boulder Creek in Colorado

Get Directions to the Fishing Access Points shown above with the DIY Fly Fishing Map

Best South Boulder Creek Fishing Spots

To reach the South Boulder Creek headwaters, head north on the 119 past Blackhawk until you get to Rollinsville. Head west on Rollins Pass road from here to follow the creek itself.

Headwater fishing is decent, and there is a fair amount of public land up here, but as always be on the lookout for posted signs as you make your way along the banks.

If you prefer to stay below the headwaters but above the reservoir for your excursion, get on Highway 72 West from 93 through Coal Creek Canyon until you get to Pinecliffe. It’s all public land from the stream gauge until you get to the reservoir.

For tailwater angling, take Highway 72 West from 93 North of the city of Golden, then take the exit/turnoff for Gross Reservoir. Access to the tailwater section is via the Walker Ranch Open Space.

To fish Eldorado Canyon State Park, take Highway 93 North out of Golden until you get to Highway 170. Take 170 west until you get to the entrance of the park. Keep in mind there is an admission fee per carload if you park there and per person if you walk into the park.

There is a designated fishing area that stretches for about a mile along the bottom of the canyon.

Best Time to Fish South Boulder Creek

The best time of year to fish South Boulder Creek is the summer and fall. Large hatches of Baetis are common during this time of year on the middle section between the headwaters and the reservoir. Below the reservoir Mysis shrimp flies are the ticket. The fattened trout in the tailwater love shrimp! 

Winter fishing is possible, but the intense cold and frozen river flow in places may be too much for some. Runoff tends to muddy the waters a good bit, so early spring makes for tough fishing.

Best Flies for South Boulder Creek

Here are some recommended fly patterns for South Boulder Creek:

  • Parachute Adams (grey #18)
  • Griffith’s Gnat (black thread#18) 
  • I Can See It Midge Fly (black #22)
  • CDC Loopwing Quill Emerger (Dark #16,18,22)
  • Mysis Shimp (white #18)
  • Prince Nymph (peacock #12-18)
  • Vernille San Juan Worm (clown Pink#16)
  • Bead Head Brassie™(peacock #18 – 22)
  • Brownstone (brown #14)
  • Zebra midge (dark #20 – 24)
  • Micro streamer (white, black, yellow, green #8)

South Boulder Creek Fishing Tips

A 8-1/2 foot 4-wt fly rod with floating line is perfect for fishing dry flies and nymphs on the South Boulder. A tapered 9-foot leader, with tippet size 3X to 5X to match the flies you are throwing, is pretty standard.

South Boulder Creek Fishing Reports

There are a number of area fly shops and on-line retailers that publish South Boulder Creek fly fishing reports. A few to check out are listed below.

South Boulder Creek Fishing Regulations

Beware of the posted notices marking private property lines on South Boulder Creek, as the public access state land is directly adjacent to many ranches and other private properties.

Anglers should also be aware that walking along the train tracks is considered trespassing on Amtrak land, and passenger and freight trains pass by throughout the day. 

On public land above the Gross Reservoir and for most of the tailwater, anglers need only follow standard Colorado Division of Wildlife fishing regulations. Watch out for the area just below the reservoir though as access is restricted.

South Boulder Creek Trip Planning Tips

The best deals will most likely be flying into Denver and then driving out to Boulder or Golden for accommodations.

There are the traditional hotel and motel accommodations, as well as ski lodges, ranches, and local bed and breakfast places that cater to the fishing, hiking, and hunting crowd year round.

Both cities are hot spots for tourists throughout the year though, so make sure if you do plan to go that you book well in advance.

Don’t forget to check out local vacation rental listings as well, since many offer deals during the slow season to the flexible traveling angler.

Looking for more places to fish? Visit our DIY Guide to the Best Fly Fishing in Colorado.

Feature image by Jeffrey Beall