A huge arid expanse defined by its lack of any exterior drainage, the Great Basin sprawls across the interior west, covering much of Nevada, southeastern Oregon and southern Idaho. Immediately north, the Snake River breathes agricultural life into the desert regions bordering the Great Basin. All across this huge chunk of real estate, ranchers and farmers have for several generations relied on storage reservoirs and modern irrigation projects to reap a living from otherwise inhospitable environs.

The Steens Mountains provide a spectacular back-drop for Oregon's Mann Lake which offers Lahontan Cutthroat (below) ranging from 14- to- 24 inches.

Many of these reservoirs reside on public lands and--thanks to stocking efforts by state fish and game agencies-offer some of the best trophy trout action in the west. Waters like Idaho's Chesterfield Reservoir or Oregon's Malheur Reservoir exhibit remarkable growth rates for planted rainbows: A three-year-old Chesterfield trout might span 24 inches in length and weigh five or six pounds. In addition to these fertile reservoirs, the interior west offers a precious few natural lakes, some of which now offer exceptional fisheries for Lahontan Cutthroat trout, a sub-species supremely adapted to the alkaline waters of the Great Basin.

Great Basin fisheries depend entirely upon water supply. During periods of extended drought, irrigation storage reservoirs yield most of their water to local agriculture, decimating trout fisheries. During normal years with ample water supplies, the reservoirs remain fishable throughout the season, peaking from mid-spring through early summer and again during the autumn (prospects for this year are good). Always check with local shops or fish and game agencies before venturing to any of these reservoirs-make sure the water level has been stable for two or more years. Also, some of these waters are prone to infestation by chubs, perch or other such undesirables and a quick phone call can save you the trouble of driving many miles to a reservoir devoid of fish owing to recent rehabilitation.

A nice rainbow from Sheep Creek Reservoir, Duck Valley Indian Reservation, Nevada.

The arid-country reservoirs of the interior west offer little in the way of amenities. Camping facilities would make a caveman cringe. With few exceptions, the typical layout features a flat spot and maybe a haphazard fire-ring. Shade trees, if they exist, form the most coveted asset at any given reservoir. This is sagebrush country and sagebrush offers barely enough shade for a jackrabbit. So bring your own shade, bring your own shelter, bring your own firewood and bring your own drinking water.

ICEOUT   Sometimes the ice comes off sooner, but these dates are a safe bet.   Wildhorse:  Early April   Big Springs:  Late March   Daniels:  Late March   Chesterfield:  Late March   Sheep Creek:  Early April   Thief Valley:  Late March   Malheur:  Mid-March   Mann Lake:   Early March

Weather can change by the hour on the high desert and most of these reservoirs reside at elevations ranging from 3,000 to more than 6,000 feet. In this land of wind-blown wide expanses, winter looses its icy grip begrudgingly and spring arrives in fits and starts. One minute you cast effortlessly over a glassy surface on a sun-bathed desert morning and an hour later you hunker down in your tube, bracing against a relentless wind and wondering how those gray clouds gathered so quickly. Then, just when you think the day is wasted, the weather breaks and reveals a brilliant scarlet-hewed sunset accompanied by a rush of trout action. Such is life on the desert reservoirs.

Given the extremes of weather, anglers must arm themselves with all manner of provisions. Carry extra gasoline, one or more spare tires and perhaps even tire chains. Never trust the dirt access roads, whose inevitable deep ruts belie their gooey nature when pelted with even minimal amounts of rainfall or snowmelt. On numerous occasions I've seen 4X4 vehicles hopelessly buried to their axles.

Float tubes, pontoons and small boats dominate these reservoirs for good reason: The angler afloat has the advantage. Sometimes you can stalk the shorelines early in the morning and sight-cast to fish feeding in just inches of water. Most of the time, however, the action occurs off shore. Most of the waters offer expansive shallow littoral zones replete with weed growth. Some, such as Big Springs Reservoir, are comprised entirely of shallow, littoral habitat--fertile, shallow areas where sunlight reaches the bottom.

Who has the advantage?>

Float tubes are better than pontoons on these waters when the wind blows, which is frequently. One favorite ploy is to take a regular boat with a motor and a float tube: use the boat to get where you're going and then fish from the tube.

Expect to fish attractor-style flies most of the time. Leech patterns, Carey Specials, Staynor Ducktails and several other general-use patterns produce plenty of action a majority of the time. When hatches occur, however, the trout often feed selectively. The primary hatches on these waters include damsels, Chironomids and Callibaetis mayflies. Chironomid larvae and scuds abound, so like-imitations usually do the trick and sometimes out-fish any other patterns.

On your inaugural visit to any particular reservoir, pick out a likely looking shoreline, paddle off shore a ways and begin fishing your favorite confidence patterns. Use a cast-and-retrieve approach or simply drag flies behind until you locate fish. New-generation intermediate and slow-sinking lines are a virtual Godsend for reservoir enthusiasts. Scientific Anglers' Stillwater Line or Cortland's Clear Camo Line fish at any level save the deepest areas and are perfectly suited to these waters, where most of the action occurs in depths ranging from 5 to 12 feet. All the major line manufacturers now offer lines of this type. Match your tackle to the fish and the conditions. Six- and seven-weight rods cast all sizes of flies and can handle the 14- to 25-inch bruisers you will encounter on these waters. In addition to the aforementioned intermediate or slow-sinking line, carry a floating line and a fast-sinking line. Some years ago I purchased an aquatic sampling net with a foot-wide catch bag and an eight-foot handle. This sampling net allows me to reach down into the depths and see what critters are swimming about.

Tim Blount battles a Chesterfield Reservoir rainbow in Idaho.