The site contains the largest concentration of rare grassland birds in New England. Roughly 50 percent of the state's Grasshopper Sparrows and fewer than 75 percent of the state's Upland Sandpiper breeding populations are on the site. Many other high-conservation-priority species associated with open habitats regularly breed on the facility including the American Kestrel, American Woodcock, Black-billed Cuckoo, Eastern Kingbird, Brown Thrasher, Prairie Warbler, Indigo Bunting, Eastern Towhee, Field Sparrow, Bobolink, and Eastern Meadowlark. In addition, there are good numbers of Blue-winged Warblers and Gray Catbirds nesting, representing significant proportions of the breeding populations of these species in Massachusetts. The base contains both native grassland habitats and cultural grasslands that are suitable for nesting grassland species. In addition, the area is regionally important as a migratory stopover point for some species (e.g., American Kestrel) and often harbors wintering open-country species such as the Snowy Owl and Snow Bunting. This site is also important as a location for long-term monitoring of grassland breeding birds including graduate research and biannual inventories by MassWildlife.

Westover Air Reserve Base is not open to the public, and anyone wishing to visit the facility must make arrangements in advance through the public affairs office.

Westover Air Reserve Base is an Air Force training base. The habitat type on the base consists of oak woodlands, extensive wetlands and vernal pools, red pine plantations, and grasslands. Grasslands cover approximately 1,600 acres. The IBA is located on the outwash plain, a remnant of glacial Lake Hitchcock. The soils in the grasslands are sandy and dry, with patches of wetlands in low-lying areas. Before Westover became a military base in the 1950s, the grasslands were referred to as Chicopee Plains, a common pasture for grazing cattle. Because of human use, grasses and forbs are a mixture of native and introduced species. Management of the grasslands at Westover consists of annual mowing after July 31. Grasslands near the runway (within 50 feet) are mowed more frequently to detract birds and insects.