River and Fishing Information

General Hatch Information for Trout Fishing in the Gunnison Valley

The following is a high-level overview of the main hatches we see here in the Gunnison Valley throughout our fishing season (March through October). Some recommended fly patterns are included as well.

March - April (early season hatches, before run-off)

The main early season hatches consist of midges and the first mayfly hatch of the season - the Blue-Winged Olives (BWOs). The BWOs can start to hatch anytime from around mid to late March to mid April, depending on weather and water conditions. These hatches will normally begin about mid day as the water temperatures rise. Fish activity will increase with water temperatures over 40 degrees.

During the early season before run-off, trout will feed on mayfly nymphs and also large stonefly nymphs. You can fish a tandem nymph rig with a big stonefly nymph pattern and small mayfly nymph trailing behind. Fish will also begin to chase streamers.

Midges:	gray, black, olive - sizes 18 to 24
BWO:	size 16 to 20
Stonefly Nymphs:	20-Incher, Rubber Legged Stones, Golden Stones - sizes 6 to 8
Mayfly Nymphs:	Barr BWO Emergers, Pheasant Tails, Copper Johns - sizes 16 to 20
Streamers:	Muddy Buddy, Sculpzilla, Wooly Bugger - sizes 4 to 8

May - June (run-off)

Run-off can be difficult to predict and it varies each season based on snow-pack and weather. Typically, you can expect run-off to begin by late April or early May. Run-off conditions can last anywhere from four to eight weeks, but it could be more or it could be less. During run-off, there are some hatches of BWOs and caddis, and also some stoneflies, but these hatches are not fishable during this time.

June - August

Peak insect activity occurs during the summer months here in our part of the Rocky Mountains. We'll see hatches of BWOs, caddis, stoneflies, Green Drakes, and Pale Morning Duns (PMDs). There is normally a good caddis hatch which continues from run-off into summer. The big Western Green Drake will begin to hatch in late June. This hatch starts in the lower part of the Gunnison River, just above Blue Mesa Reservoir. The hatch progresses up through the watershed and will eventually occur on the East River and Taylor River. The drakes will continue to move up the Taylor River to the C&R (Catch-and-Release) section below the dam. The hatch is different every year and is very difficult to predict. It can take anywhere from two to four weeks to move from Blue Mesa to Almont and beyond. We can also see PMDs hatch just before, during, and after the Green Drake hatch. There are times when the PMDs dominate. They are an important food source for the trout during summer.

BWO:	size 16 to 20
Caddisflies:	tan, olive, brown, black, yellow - sizes 12 to 20
Stoneflies:	salmon fly, golden stone - sizes 4 to 8
Little Yellow Stoneflies:	Yellow Sallies - size 16
Green Drake:	size 10 to 12
PMD:	size 14 to 18
Hoppers:	tan, yellow - sizes 6 to 10

After the major summer hatches are complete, late summer brings hoppers. August is a great time to fish big hopper patterns. In general, terrestrials can be a food source from late July to the end of August, and even into September.

Fishing dry-dropper rigs during summer can be very effective. This involves fishing a dry fly with a nymph dropped below it. (See Fishing a Tandem Rig for details.) You can also fish a hopper on top with a nymph below it (hopper-dropper). Tandem nymph rigs and streamers will also continue to work well during the summer months.

September - October

Fall can be an excellent time to fish in the Gunnison Valley. The fall hatches are limited and can be more sparse as compared to the summer hatches, but the fish are active. There is a Gray/Slate Drake hatch which can start as early as late August and run into late September or early October. In addition, there is the fall BWO hatch. These olives are very small, in the size 20 to 24 range, but they are significant. These BWOs will hatch during late August through September.

Fall is also a good time to fish streamers and egg patterns. Brown trout and kokanee salmon spawn in the fall, and they will become very aggressive prior to spawning during mid to late September and into October. Streamers can be very effective during this time. Once the browns and kokanee begin to drop their eggs, rainbow trout will move in behind them and feed on the eggs. Egg patterns are effective from early October straight through the winter months.

BWO:	size 20 to 24
Gray/Slate Drake:	size 12 to 14
Streamers:	Muddy Buddy, Sculpzilla, Wooly Bugger - sizes 4 to 8
Egg Patterns:	roe, chartreuse, cheese - size 14

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