National Parks 9 min read

DIY Guide to the Best Fly Fishing in Rocky Mountain National Park

Ken Sperry

Posted by Ken Sperry

May 24, 2024

Rocky Mountain National Park Fly Fishing

It’s hard to find a park more scenic than Rocky Mountain National Park in Colorado.

It’s here you’ll be able to take in some rather large and impressive mountains, valleys, streams, lakes, and rivers.

One of the activities that is popular in the park is fly fishing. The park offers countless opportunities on both the west and east sides.

Populations of at least four species of trout exist in the park streams and lakes including brown trout, brook trout, rainbow trout and cutthroat trout.

The only native trout in the Park are Greenback Cutthroat and Colorado River Cutthroat.

Trout Fishing in Rocky Mountain National Park

Rocky Mountain Fly Fisher provides a glimpse of what fly fishing in Rocky Mountain National Park is all about.

Since 1975, native trout have experienced intensive restoration efforts, while non-native fish are being removed and no longer stocked. Supplemental stocking is done only to restore native species.

What makes this park unique is that many of the lakes are found at high altitudes, which makes the water quite cold. This isn’t the best conditions for trout to reproduce, which makes the stocking all the more important.

So now that you’ve decided to visit Rocky Mountain National Park for a fishing trip, it’s time to find the best places to go, and figure out what kind of equipment you’re going to need.

Since many of lakes in Rocky Mountain National Park are barren (only 48 of the 156 lakes in the park have reproducing populations of fish) and most require a hike to reach, it’s important to know which have fish before planning a trip into the back country.

Lakes with trout populations are shown on the map and discussed below.  Click on the map markers for information about each fishing destination.

Rocky Mountain National Park Fishing Map

map of fishing spots in Rocky Mountain National Park

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

Best Places to Fish in Rocky Mountain National park

There are a number of spots within Rocky Mountain National Park that are well worth visiting. Some are great for that quiet fly fishing outing on your own, while others tend to be a bit more crowded and draw more variety anglers such as families.

A great way to understand how Rocky Mountain National Park is laid out is to understand it is divided into two sections. You can look for fishing opportunities on the eastern side or the western side of the park.

These “sides” are actually determined by the continental divide that runs through the park. There is no “right” or “wrong” side to fish on, instead anglers are encouraged to give both a try and discover the beauty of each side.Let’s take a look at some of the more popular spots for fishing on each side.

Let’s take a look at some of the more popular spots for fishing on each side.

Trout Fishing on Western Side of the Park

Baker Creek: Sometimes you aren’t looking to be challenged and really work hard, sometimes you just want to relax and have an “easy” day of fishing. If that’s the case then Baker Creek off the Bowen/Baker trail could be ideal. You can find all kinds of great locations along the shore where you can catch brook and brown trout.

Onahu Creek: While many of the creeks and rivers in the park aren’t very accessible and require half and even full day hikes to reach them, Onahu Creek is very easy to reach. It is located right in the middle of a meadow making for a serene and beautiful environment. The area is known for brown, brook, and Colorado River cutthroat trout.

Spirit Lake: Some people want to take on the full challenge of a fly fishing adventure, and that includes finding a location that is remote and takes quite a bit of effort to reach. If that’s the case then Spirit Lake on the East Inlet Trail is made for you. This one takes a full day to reach, so you’ll want to plan it as an overnight journey. Here you can find brook and Colorado River cutthroat trout.

Trout Fishing on Eastern Side of the Park

Black Lake: This lake can be found off the Glacier Gorge trail and is ideal for anyone who wants a fabulous fly fishing lake experience. You won’t get a lot of variety here when it comes to the trout, it’s just brook trout in this lake. Keep in mind there is a hike involved to the lake of about five miles, so you’ll want to be prepared. The lake will keep beginners and advanced anglers happy.

The Loch: This lake can be found off the Glacier Gorge as well and is perfect for those who love using dry flies. What anglers love is the fact it has a number of coves that provide protection from the wind, making fishing a lot easier. Expect to find greenback cutthroat and brook trout here.

Sprague Lake: If you’re hoping to get out early in the season, then sticking to a lake at a low altitude is best so the temperatures are a bit warmer. That is the case with Sprague Lake, which is located much lower than many of the other lakes. While fishing in this lake you’ll be able to find brook, brown, and rainbow trout, giving you a nice variety.

Roaring River: The Roaring River can be found off Lawn Lake and is a very windy location. You’ll want to keep this wind in mind as you pack your gear. This river is meant to be enjoyed wading, so again keep that in mind as you pack. You’ll find a nice variety of trout here as you are able to hook brook, brown, rainbow, and greenback cutthroat.

Mill Creek: Mill Creek is off the Follows Bear Lake Road trail and what anglers love about this spot is that it is very accessible. You can literally park your car not far from the shore, making this perfect for a day trip. Another big draw to this creek is the fact it is extremely challenging and will put your technique and skills to the test. You’ll find brook, brown, and rainbow trout here.

Where to Find Greenback and Colorado River Cutthroat Trout

Streams and lakes in Rocky Mountain National Park that contain native populations of Greenback Cutthroat Trout and Colorado River Cutthroat Trout are listed below.  

All waters containing native cutthroat trout are managed as Catch and Release Waters.  See fishing regulations below.

  • Adams Lake**
  • Arrowhead Lake*
  • Big Crystal Lake*
  • Caddis Lake (Lower Fay Lake)*
  • Cony Creek (above Calypso Cascades)*
  • Dream Lake*
  • Fern Lake and Creek*
  • Fifth Lake**
  • Forest Canyon (above the Pool)*
  • Hidden Valley Beaver Ponds and Hidden Valley Creek (open only as posted)*#
  • Hutcheson Lakes*Lake Husted*
  • Lake Louise*
  • Lawn Lake*
  • Lily Lake (south, west and north shores; east shore open July 1 to April 30)*
  • Loomis Lake*
  • Lost Lake*#
  • North Fork of the Big Thompson above Lost Falls*#
  • Odessa Lake*Ouzel Creek (above falls; brook trout may be kept)*#
  • Ouzel Lake*#
  • Paradise Creek drainage**
  • Pear Lake and Creek*
  • Roaring River*
  • Sandbeach Lake and Creek*
  • Spruce Lake*
  • Timber Lake and Creek**
  • West Creek*

*Greenback Cutthroat Trout, **Colorado River Cutthroat, # A legal limit of brook trout may be kept

Brook Trout, Brown Trout and Rainbow Trout in RMNP

Brook Trout, Brown Trout and Rainbow Trout were introduced by early settlers and are still present today in many Rocky Mountain National Park trout streams and lakes.  Below is list of destinations that contain these non-native trout species.

  • Black Lake
  • Box Lake
  • Fourth Lake
  • Haynach Lake
  • Jewel Lake
  • Lake Haiyaha
  • Lake Nanita (outlet closed)
  • Lake of Glass
  • Lake Solitude
  • Lake Verna
  • Little Rock Lake
  • Loch Vale
  • Lone Pine Lake
  • Mills Lake
  • Mirror Lake
  • Peacock Pool
  • Pettingell Lake
  • Poudre Lake
  • Rock Lake
  • Sky Pond
  • Spirit Lake
  • Sprague Lake
  • Ten Lake Park Lakes
  • Thunder Lake
  • Ypsilon Lake

Waters Closed to Fishing in Rocky Mountain National Park

Select waters are closed to fishing in Rocky Mountain National Park, including those listed below.

  • BEAR LAKE, inlet and outlet streams, extending 200 yards downstream
  • HUNTERS CREEK above Wild Basin Ranger Station, as posted
  • LAKE NANITA OUTLET downstream 100 yards
  • SOUTH FORK POUDRE RIVER above Pingree Park
  • UPPER COLUMBINE CREEK above 9,000 feet
  • LILY LAKE east shore May-June

Due to the dynamic nature of fisheries management, fishing regulations could change at anytime. Special closures may be put in place above and beyond what is listed here. Please contact the park before your fishing trip for current information.

When to Fish Rocky Mountain National Park

One downfall with Rocky Mountain National Park is the elevation that makes it so cold here means the fishing season is very short. It is much shorter than other national parks around the country, so you really need to be sure to visit at the right time of year.

Come January there is absolutely nowhere to fish in the park, as all the water is frozen over completely. So what is that best time of year?

Technically the fishing season runs from April to October, but the mid part of the season is really the best time, in particular for lake fishing. That means July, August, and September.

Often you have to wait until these months for the ice to completely clear off the water, especially water that is located high in the mountains. The one downfall is that everyone is doing the same thing, waiting for these months, so fishing can be a bit busy and crowded depending on where you go.

Rocky Mountain National Park Hatches

The hatch season is a bit shorter and smaller here in Rocky Mountain National Park compared to some of the other more southern parks. Hatches typically begin (reliably) in April with midges, mayflies, caddisflies and stoneflies.

From there damselflies, grasshoppers, crickets, ants, and beetles are also on the menu (usually in May or June). All hatches of all types start to peter out by the end of October.

Best Flies for Rocky Mountain National Park

Picking the best flies will ensure that you manage to have a very successful fishing outing. Dry flies, small streamer patterns, and even soft hackles can make for a great option. You may want to try a variety and keep in mind that it will also depend on the river/stream that you’re fishing in.

Tried and true patterns include flies such as Adams dry fly, parachute hoppers, Hare’s Ear and Pheasant Tail nymphs. Paying attention to the hatch at that time of year will also help you to pick the right flies.

Best Fly Fishing Gear for RMNP

For fishing in the Rockies it’s best to opt for an eight-foot 3- or 4-wt fly rod for the the smaller streams.  If you are fishing the alpine lakes, a standard 9-foot, 5-wt fly rod is a good choice.

When it comes to your tippet you can go with 6x when dealing with fish that are more “difficult”, 5x when nymphing, and 4x for use with streamers.

There are wading opportunities as well, so bringing along a pair of high-quality hip boots or chest-high waders is a good idea.

Rocky Mountain National Park Fishing Regulations

A valid Colorado fishing license is required for persons 16 years of age or older to fish in Rocky Mountain National Park. No other permit is necessary, however it’s your responsibility to know and obey applicable regulations.

To obtain current Colorado fishing license fees visit the Colorado Division of Parks & Wildlife web site.

Fishing Methods

  • One hand-held rod or line per person.
  • A second rod stamp is not honored in the Park.
  • Bait and worms are not permitted in catch-and-release waters.
  • Use of lead sinkers (or other lead fishing materials) is strongly discouraged.
  • Artificial lures or flies with one (single, double, or treble) hook with a common shank may be used.
  • Artificial flies or lures applies to devices containing materials such as wood, plastic, glass, hair, metal, feathers, or fiber, designed to attract fish.This does not include: (a) any hand moldable material designed to attract fish by the sense of taste or smell; (b) any device to which scents or smell attractants have been externally applied; (c) molded plastic devices less than one and one-half inch in length; (d) foods; (e) traditional organic baits such as worms, grubs, crickets, leeches, minnows, and fish eggs; and (f) manufactured baits such as imitation fish eggs, dough baits, or stink baits.
  • Fly fishers may use a two hook system, where one hook is used as an attractant.
  • While in possession of any fishing equipment, bait for fishing (insects, worms, fish eggs, minnows or other organic matter) is prohibited. Children 12 years of age or under, however, may use worms or preserved fish eggs in all park waters open to fishing except those designated as catch-and release areas.

Possession Limits

This is general information only. Regulations are subject to change as conditions warrant. Consult a Ranger before setting out for the latest information. A complete list of regulations is available at park visitor centers and ranger stations.

POSSESSION LIMIT: 8 fish, 6 must be brook Trout

Catch and Release Waters

Certain waters in the park with restored native fish populations are open year round during daylight hours, except as indicated. Use barbless hooks only. Any and all fish species taken must be immediately returned to the water unharmed. No bait is permitted by any age angler in catch-and-release areas.

Choosing Rocky Mountain National Park as the destination for your next fly fishing adventure means you’re in for some fabulous and unbeatable scenery, adventure, and some rather challenging fishing experiences. Since the fishing season is shorter in this park, you’ll want to be sure you plan your trip for the best point of the season.

Additional Resources

A Fly Fishing Guide To Rocky Mountain National Park by Steven B. Schweitzer – this is the bible when it comes to fly fishing in Rocky Mountain National Park.  If you don’t have a copy – get it!

Looking for more places to fish?  Check our DIY Guide to the Best Fly Fishing Destinations in the U.S.