North Platte Tailwaters

Two fine tailwater fisheries--known as the Miracle Mile and Gray Reef--are the by-products of these irrigation/hydro projects. These relatively short river sections are nutrient rich, and support huge populations of scuds and other invertebrates. Trout feed on this protein-rich banquet 365 days a year, often growing to weigh 5 pounds or more.

Due to the abundance of food, fluctuating water temperatures, frequently adverse Wyoming weather conditions, and other factors, these trout are not always easy to catch. But with a little luck and knowledge, or a great deal of persistence, you can hook and land the trout of a lifetime.

The Miracle Mile is accessible from the north (Casper) and the south (Rawlins) although portions of both unpaved roads are less than desirable, especially in the winter. There are no private sections, so an angler can walk and wade at will. There is a low bridge on the river halfway between the two reserviors, which makes floating more of a nuisance than an advantage. On Gray Reef, wade access is limited to the first mile of river, and most anglers float from the Gray Reef Access to Lusby's or from Lusby's to Government Bridge. Click here for a map.

Tailwater Seasons
Wild weather and walleyes. Spring is a transitional period--the weather can be absolutely beautiful or downright nasty and the fishing seems to have similar mood swings. Rainbow trout run up out of Pathfinder Reservoir and stack up with their fluvial relatives below the riffles where they will eventually spawn.

These prespawn fish will still eat, and a large streamer will help you find the most aggressive, and often the largest, in the bunch. Traditional nymphing techniques can still be effective with scuds, midge pupa, and egg patterns fished deep along the bottom.

When the rainbows begin spawning, they'll move right into the shallow, riffle water, and brown trout will hold downstream and gorge on eggs caught in the drift. Later in the spring, Baetis nymphs mature and the fish start looking for them. Small Pheasant Tail nymphs or more specific Baetis nymph imitations are good choices, especially in the afternoon when the naturals are most active.

Thousands of Walleye run up into the Mile from Pathfinder Reservoir during the month of April, offering the relatively unusual opportunity to catch these fish on a fly. Look for them early in the month in the deep pools at the bottom end of the Mile. These fish can be taken using sinking-tip lines or shooting-heads, and working a streamer pattern slowly across the bottom of the deep pools.

Opportunities for finding and fishing to rising trout increase at this time of year, especially on calm days. Midges start hatching in enough numbers to get trout to the surface in the slick, quiet water. Anglers will often see fish rising out in the current in enough numbers to get them excited. However, these fish are not the kind that hold in one spot and continually sip insects off the surface; they are sporadic risers, usually chasing emergers, and moving after the rise.

A small soft-hackled imitation is deadly on these fish and fishing it couldn't be easier. Simply cast it above the rising fish and allow it to swing through the trout's window. Cast into the faster water and allow it to swing into slower water. Move down the run, or modify the length of your cast to make sure you cover all the water. Strikes will come, but because of the hooking angle, getting solid hook-ups is difficult at times.

When both wind and water flows are moderate, the spring Blue-Winged Olive hatch will definitely bring fish to the surface. These insects will hatch out of the riffles and fish can be found in the quiet eddies along the riffles and in the slower water downstream. Any of the traditional BWO dun, transitional dun, or emerger patterns will effective on these fish as will a small parachute Adams.

Crowds and classic hatches. Summer is obviously the time of major insect activity as well as angler activity. Be forewarned--it can be extremely crowded, especially on weekends.

Most of the mayfly nymphs have matured and are ready to hatch. Caddis larva and stonefly nymphs become very important to the trout and the angler. While scuds still make up a large portion of a trout's diet, they become less important as other insects become available.


While rainbows and browns are the most common catch, golden hued Snake River cutthroat trout are also present in both the Miracle Mile and Grey Reef.

Caddis hatch over the course of the summer and larval imitations will bring fish to the net. The Pale Morning Dun is the premier mayfly of the summer months and its nymph is mature and available to the trout. Little Yellow Sallies are a dominate insect during the summer months and its nymph plays an important role in a trout's diet.

Most of these insects' nymph or larval behavior can be best matched by dead-drifting an imitation along the bottom through traditional "nymphing" waters. This will imitate insects that are caught in the drift. Some of the caddis, as they pupate, exhibit some swimming action, so an imitation occasionally twitched to lifted off the bottom will be very effective.

The Yellow Sally nymph will swim to slower water and eventually crawl out onto anything protruding from the water's surface or onto shore. This swimming activity can be matched by retrieving an artificial in short strips through the slow water along the bank. This is the time of year to try a variety of patterns, although a general Hare's Ear or Red Fox Squirrel type pattern will do well. A quick sampling with a kick screen should give you an indication of what is available, what sizes are prevalent, and what colors are dominant.

Wet flies, soft-hackles and emerger patterns come into play during the summer months. The natural behavior of much of the available food lends itself to traditional wet fly swings. Simple fishing techniques often have surprising results on this water. Evenings are a particularly good time to use these techniques and fly patterns.

Dry-fly fanatics will likely be disappointed with the quality of fishing during the summer months. The constantly fluctuating water levels prevent large numbers of fish from rising to the surface. Still, some fish will occasionally look to the surface to feed, but it is usually rare to find them holding in traditional areas, continuously sipping adult insects off the surface. Look for small pods of rising fish in isolated areas for success. In years that have relatively constant flows, fish will respond to the hatches and become accustomed to feeding at the surface.

Terrestrials play a minor role in the overall scheme of summer fishing. The occasional beetle or hopper imitation will take a fish here or there, so they are worth a try. Ants are important to the summer angler, especially so during a swarm--they get blown into the water and fish do look for them. Play close attention to the water's edge, especially if there is nearby vegetation.

Toward the end of summer--starting at the end of August and often lasting through September and into October--the water becomes roiled and full of debris. The reservoirs upstream "turn over" and send crud down through the mile. Fish can still be taken, but in my opinion, it isn't worth a trip to fish for them.

Big browns and baetis. late fall, after the water clears, is an exciting time of year. Crowds dissipate to a degree, the weather remains good (with the exception of early storms) and fish are willing. Brown trout begin staging, prior to spawning, in some of the deep channels and provide for some exciting nymph and streamer fishing. Later, in November, they will actually begin spawning, and rainbows and non-spawning browns will hold downstream and eat the eggs caught in the current.

Miracle Mile rainbows feed on brown trout eggs during the fall, and are often found in the drop-offs directly below the riffles.

There can also be excellent hatches, especially on overcast or "spitting snow" days, of fall Baetis. Many fish will hold in tailout sections of the river and feed heavily on these mayflies. The fall species of Baetis emerges under the surface of the water as it ascends to the surface. Trout generally key to this and a small generic soft-hackle or RS-2 will be surprisingly effective either dead-drifted or swung in front of feeding fish. There can be some spectacular fishing during this hatch.

Winter fishing. Wyomings winters are only for hardy souls. Wind and air temperatures can make for some extreme fishing, but it is worth it. Fewer fisherman will be on the water than during the balmy days of summer, so you will have more space to yourself. Water flows are usually more stable, so the fish are more accessible. It's also worth the discomfort because the odds of catching a truly large fish better during the winter than at any other time of year.

According the Wyoming Fish and Game Department, early February is the prime time to hook one of these locomotives. The largest trout seem to hold in slower water--often right below an upstream riffle or reach of fast water. They also seem to hold in pods of similarly-sized fish (little fish rarely hold with large fish) and if one of these pods can be located, an excellent day is in store.

Nymphing with scud imitations is the ticket for most winter fishing. There is a minor spawning run of rainbow trout that comes out of the reservoir around Christmas and a small egg pattern is often very effective on resident trout looking for eggs. Midges are important during the winter and a red midge worm, dead-drifted along the bottom with a scud, can be deadly.

Dry-fly enthusiasts can find fish rising to midge adults, especially in early December and late February. In years where there is no major cold snap, midges may be found on the surface all winter long. There is also a small dark stonefly that hatches in scattered numbers. If conditions are just right, a fish or two may be taken on the surface with a small Stimulator. Fish holding tight to a willowy bank are the most likely to take an interest in this type of offering.