Spring Hatches
Baetis Mayflies
March Brown Mayflies

As the snow recedes, the days grow longer, and the warming weather feels like it's here to stay, we start thinking seriously about the opportunity to do some serious fishing before runoff.

If you're headed to tailwaters or slow paced/low gradient streams midges will continue to dominate. I've found gray, black or dark olive to be the most predominant. Be prepared with adults, pupa, and larva imitations. I'll fish two flies, adults & pupa or pupa and larva. Keep in mind that many fish that appear to be rising are taking the pupa just under the surface - watch closely. Carry a good selection of small sizes meaning 22 to 26. There are times the fish will simply ignore the larger imitations. I recall a trip to the Dream Stream last year. I was fishing a size 22 beadhead RS2 and my partners were using 24 and catching 4 times the number of trout that I was. When I downsized my luck changed immediately.

On freestone rivers little black and brown stone flies can be a good bet. These insects are most active on warm sunny days. Size 10 to 16 beadhead prince nymphs and/or dark stimulators seem to fish best. Golden Stones become available to trout in moderately fast streams starting in late March or early April. An old-time dry fly pattern which always seems to produce is the Colorado King (doubles as a caddis pattern). Try George's Stone or Kaufmann's Golden Stone for the nymph imitation. In rivers where these insects are found in abundance caddis flies are generally of equal importance.

Caddis flies start their primary emergence in April and continue through October or early November. There are some 75 species of these insects along our Front Range. Only three are active early in the year - little autumn stream sedge (dark olive), the tan short horn sedge, and the Grannom (olive or green). In general they become most active late in the day but weather always dictates. Almost every fly fisherman is aware of the "Mothers Day Hatch" of Grannom caddis flies so named for the time of year of the emergence. In Colorado the Arkansas is widely known as the place to go when this hatch gets underway. The hatch begins in the Canon City area in mid-April and gradually moves upstream past Salida until runoff around mid-May. If you hit it right the number of hatching insects can be staggering. They form rafts on the water and stack up in eddies. Fishing the hatch with a combination of wet and dry fly imitations is a good approach. Try a partridge & peacock, western coachmen (use various darker synthetic wing materials) or Sparkle Emerger wet flies and dark elk hair caddis drys. Early in the hatch is generally better. My advice is to call or watch the Royal Gorge Anglers reports for the right timing - http://royalgorgeanglers.com.

Mayflies are an extremely important component of the trout's diet, however, early in the year only it's the Baetis mayflies that are the predominant species. They can start appearing at the same time the caddis become available and come off in larger sizes (14 to 18) that get progressively smaller heading into early summer (20 to 24). An overcast slightly humid day offers perfect conditions for a Baetis hatch. Most anglers refer to these flies as Blue Wing Olives due to their coloration (olive grey to olive brown with medium grey wings). They generally appear in the early afternoon but weather will dictate. A typical scenario on many rivers is midges in the morning and BWO's in the afternoon.

Patterns for BWO's include pheasant tails nymphs and all the variations used on this fly, RS2's, Compara Duns, Parachute Adams, Sparkle Duns, and the list go on and on. One of the elements that makes this a particularly exciting hatch to fish is that the duns stay on the water for a considerable period of time giving the trout plenty of time. While most of the fish will be concentrating on the emergers there will be plenty of opportunity for dry action. I've found the number one issue with this hatch is getting the size right - better to err towards the smaller sizes. One you've got the size right getting a drag free float right down the feeding lane will almost always produce a take.

Don't forget other imitations that work all year round - cranefly larva, scuds, and aquatic worms (San Juan Worms).