Colorado Fly Fishing 3 min read

DIY Guide to Fly Fishing the Upper San Juan River in Colorado

Ken Sperry

Posted by Ken Sperry

May 24, 2024

Upper San Juan River

Making its headwaters in the Colorado high country not far from Wolf Creek Pass, the San Juan River actually travels the majority of its overland journey through Utah and New Mexico.

By the time the San Juan reaches Pagosa Springs, it is already a wide flowing river. If you keep following it downstream another 25 miles or so, it empties into the Navajo Reservoir.

The San Juan in Colorado flows rather conveniently through Pagosa Springs, providing easy access to the local hot springs as well as excellent trout fishing conditions.

An angler can fish all morning, break for lunch and maybe a soak in the hot springs, then get right back out on the river for the evening hatch.

About Upper San Juan River

Fly Fishing San Juan River in Pagosa Springs, Colorado

Follow the San Juan all the way to the Navajo Reservoir, and you will need to have a New Mexico fishing license. The legendary trout of the San Juan are generally found below the dam at the Navajo Reservoir in New Mexico, and it is well worth the time and effort if you don’t mind making a day trip from Pagosa Springs.

San Juan River Fishing Access Sites in Colorado

map of fishing access spots on the Upper San Juan River in Colorado

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

Best Places to Fish the San Juan River in Colorado

Access to the headwaters of the San Juan River can be achieved via the National Forest Land off Highway 160 west of Wolf Creek Pass if you want to hit the West Fork. East Fork anglers should take Forest Road 667 east of Highway 160 for about 10 miles south beyond the pass.

The easiest spot to get to the San Juan is in Pagosa Springs, where the river passes right through town. The town of Pagosa Springs actually has a standing agreement with the local riverfront property holders that allows anglers permission to fish and access to the high-water mark.

Since this is not typical of Colorado law in other towns, you should take advantage during your visit to the San Juan. Additionally, there are quite a few parks in town that provide access to the river, too.

South of Pagosa Springs, you will be in Southern Ute territory, and you need both tribal permission and a special license to fish the waters of the San Juan on their land. Last but not least, the real river monsters can be found below the Navajo Reservoir Dam, right on the border between Colorado and New Mexico. Make sure you have licenses for both states before setting out. 

San Juan River (Colorado) Flow and Current Conditions


  • Streamflow: 138 ft³/s
  • Gage height: 4.01 ft
Streamflow GraphGage height Graph

Best Time to Fish the San Juan in Colorado

The upper San Juan fishes best after spring runoff which typically occurs in late May / early June.  July through September is prime time with consistent caddis hatches.  PMDs make an appearance in late July, and the blue-winged olives come off in September and October.

Best Flies for San Juan River (Colorado)

Popular fly patterns for the San Juan River include:

  • Woolly Bugger (brown, black, natural #8, #14)
  • Lynch’s Double Dot Egg (orange blood dot #18)
  • Griffith’s Gnat (black, olive #18)
  • Rojo Midge (gray, olive, brown #20 to #22
  • Rosenbauer Parachute Beetle (#black #10 to #24)
  • Cartoon Hopper (gray, olive, brown flash #6 and #8)
  • Poly Wing RS2 (brown, black, gray #18 to #24)
  • Foam Wing RS2 (brown, black, gray #18 to #24)
  • Bunny Leaches (black, olive, gray, natural, white #6 and #8)
  • Egg Patterns (chartreuse, orange, red, pink#8 to #22)

Fly Fishing Tips

A 9-foot 5-wt fly rod with floating line is perfect for fishing dry flies and small nymphs on the main stem of the San Juan River. For the smaller waters of the East and West Fork San Juan River 3- or 4-wt rod is plenty. A tapered 9-foot leader, with tippet size 3X to 5X to match the flies you are throwing, is pretty standard.

San Juan River (Colorado) Fishing Reports

There are a number of area fly shops that publish San Juan River fly fishing reports. A few to check out are listed below.

Trip Planning Tips

The closest airport for the Colorado section of the San Juan is the Durango/La Plata Airport, though if you don’t mind the drive you can fly into Albuquerque, NM 2.5 hours away. Flights are also available to Farmington, NM that will cut the drive down to as little as 40 minutes if you are looking to fish the southern reaches of the San Juan as well.

As for places to stay, the best accommodations period are going to be in Pagosa Springs. You can walk from where you are staying and get right to fishing. There are bed and breakfasts, motels, hotels, and all manner of other accommodations to suit any budget or personal taste.

There are also many campgrounds along Highway 160 as it follows the San Juan for the more adventurous, and of course there are also ski resorts within an hours drive that can provide off season accommodations for bargain prices.

Don’t forget to check out local private vacation rentals either, as they can yield excellent stays for far less than you’d spend at a comparably appointed hotel.

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