Hood River milk-vetch is an attractive perennial wildflower with many clustered, ascending to erect stems from 4-30 cm high. Plants are greenish to grayish-hairy with the herbage of consisting of short, dense gray hairs or looser appressed to spreading hairs. The 17-37 leaflets on the compound-pinnate leaves are narrowly linear and measure 5-10 mm long.
The flower stems are fairly stout and measure from 20-30 cm long, capped by a fairly congested (at least in flower ) raceme of 7-35 flowers which are held upwards or slightly ascending (See photo at right.). The whitish calyx tube is covered with white to gray, appressed to somewhat spreading hairs. The calyx measures 11-15 mm long with narrowly awl-shaped teeth about one-half to as long as the tube. The calyx tube is about 1.5 times as long as thick. The whitish corolla measures 15-18 mm long with the banner rising at an angle of about 45-50 degrees from the axis of the wings and keel. The narrow wings are much longer than the keel and shorter than the banner. The pods are erect, nearly sessile, fleshy while green and covered with gray black hairs. The pods measure from 15-20 mm long.
Idaho Milk-vetch: Astragalus conjunctus - Calyx cylindrical, 6-15 mm long, about 2 times as long as thick. Calyx teeth 1.5-3 mm long. Corolla white or with purplish tip to keel and banner. Leaflets 13-31. Pod glabrous. Found from Wasco County, northcentral Oregon east to the Blue Mts. and south to the the Steens Mt. and east to southwestern Idaho.
Hood River Milk-vetch: Astragalus hoodianus - Calyx bell-shaped, 11-15 mm long, about 1.5 times as long as thick. Calyx teeth 4.5-7.5 mm long. Leaflets 17-37. Pod pubescent. Found near the Columbia River Gorge in Wasco and Hood River Counties in Oregon and Klickitat County in Washington.
Yakima Milk-vetch: Astragalus reventiformis - Calyx bell-shaped, 8-12 mm long, about 1.5 times as long as thick. Calyx teeth 2.5-5 mm long. Leaflets 17-37. Pod pubescent. Found from Kittitas County in Washington near Ellensburg south to Klickitat County, Washington and south into Sherman County of Oregon.
Blue Mt. Milk-vetch: Astragalus reventus - Leaflets 23-41. Pod glabrous. Found in the Blue Mts. of northeastern Oregon near the headwaters of the Umatilla and Grande Ronde Rivers into southeastern Washington.
Sheldon's Milk-vetch: Astragalus sheldonii - Leaflets 23-41. Pod usually pubescent. Found from southern Asotin County in southeastern Washington south into Wallowa County, northeastern Oregon and into Lewis and Nez Perce Counties in Idaho.
Hood River milk-vetch may be found in the sagebrush desert, scablands, grasslands, ponderosa forests, and stony flats from the foothills into the lower mountains.
Hood River milk-vetch is distributed at the east end of the Columbia River Gorge through Wasco and Hood River Counties in Oregon and Klickitat County in Washington.