Description - Lying 12 miles northeast of Rupert in the Snake River Valley in south-central Idaho, the refuge extends upstream about 25 miles from the Minidoka Dam along both shores of the Snake River and includes all of Lake Walcott. Over half the refuge is open water, with some small marsh area.
Concentrations of up to 100,000 ducks and geese have been documented during spring and fall migrations, and close to 500 tundra swans can be seen as they migrate through in the spring. The refuge also serves as a molting area for waterfowl in summer. Of the 28 species of waterfowl that use the refuge, those most commonly seen are the Canada goose, mallard, pintail, redhead, gadwall, and wigeon.
Colony-nesting birds on the refuge include the Clark's and western grebe, double-crested cormorant, great blue heron, California gull, snowy egret, cattle egret, black-crowned night-heron, and American white pelican. Bald eagles are regularly observed on the refuge in fall and spring, and peregrine falcons are occasionally seen as they migrate through in fall.
Most of the upland areas are shallow soils underlain by fairly recent basalt lava flows, with an occasional sand dune scattered throughout. This mix of rock, sand, and shallow soil supports a diversity of small mammals, reptiles and invertebrates.
The divergence point of the Oregon and California Trails was about a mile south of the refuge boundary and an alternate route of the Oregon crossed the northern part of the refuge.
Climate - The climate is semi-arid with about 11 inches of precipitation per year, much of it falling as snow during the winer. Summers are hot and dry with highly variable rain during thunderstorms. Winters are generally modrate but windy. The elevation is about 4,200 feet.
To reach the refuge office and Walcott State Park, take Route 24 northeast from Rupert, Idaho; there are some tricky turns in Rupert so watch the signs carefully. About 5.5 miles from Rupert, turn right on the Minidoka Dam road and follow it to the refuge.