Windsor Grasslands are located along Marton Road in Windsor. From downtown take State Street west to Hunt Street and then a right turn on Marton Street. Park across from Pond Road and walk east. The old orchard is a good area for birding but Pond Road has some interesting habitat also.
From Jim Block

Windsor Grasslands Wildlife Management Area is one of Windsor County’s premier bird-watching destinations. Bird watching is at its best during spring and fall migrations and nesting seasons, although other times of the year can be rewarding. The wetland and adjacent fields near the intersection of Marton and State Farm Roads host a nesting pair of Northern Harriers, one of very few nesting sites for this species known to occur in eastern Vermont, as well as nesting American Kestrels. Northern Shrike and waxwings (Cedar and Bohemian) frequent this area during winter. Look for nesting Blue-winged Warblers and possibly rarer Golden-winged Warblers in old apple orchards and early successional woodlands. Courtship flights of Wilson’s Snipe and American Woodcock may be seen and heard from spring through early summer.
From Aschutney Mountain Audubon Society

Bobolink, Savannah Sparrow, Eastern Towhee, Field Sparrow, Blue-winged Warbler, Golden-winged Warbler, Prairie Warbler, Northern Harrier, American Kestrel, Northern Shrike, Cedar Waxwing, Bohemian Waxwing, Wilson’s Snipe, Woodcock

Windsor Grasslands Wildlife Management Area is the newest addition to the Vermont Fish and Wildlife Department’s extensive system of public lands conserved and managed for wildlife habitat and wildlife-based recreational uses including hunting, fishing, trapping, and wildlife watching. The WMA consists of 826 acres of woodlands, open fields, wetlands, and old orchards. Formerly it was part of the Southeast State Correctional Facility (long known as the Windsor Prison Farm). When the State announced plans to liquidate much of the prison property that was identified as not essential to the correctional facility’s mission, various interest groups stepped up to express their vision for future uses: residential and commercial development, agriculture, wildlife habitat, recreation, etc. Ascutney Mountain Audubon Society took a prominent role in the ensuing discussions with the state, town officials, and legislative representatives and sought the establishment of a WMA, where habitats will be managed for grassland birds (e.g. Bobolink, Savannah Sparrow) and “old field” species (e.g. Eastern Towhee, Field Sparrow, Blue-winged and Prairie warblers). In 2018, Windsor Grasslands WMA was officially established. AMAS continues involvement with the WMA by maintaining bluebird and kestrel nest boxes and lending support to the State in its efforts to manage habitat for birds.

Directions from downtown Windsor: At the Main Street (US-5) and State Street traffic light go west on State Street to the intersection with County Road. Here, continue straight onto Hunt Road and drive 2.2 miles to the intersection with Marton Road. Turn right onto Marton Road and drive 1.2 miles to the hilltop overlooking large open fields to the east. Limited parking is located at the red pump house near the intersection of Marton Road and State Farm Road.