With GPS, enter 300 Sunset Lake Rd, Newfane VT 05362 (since Williamsville is in Newfane township). From Williamsville Rd (aka Depot Rd), take a sharp left on Sunset Lake Rd up the hill from its start at the historic concrete bridge (now under reconstruction, which doesn't affect this route). Right in 1.4 mile at the Manitou sign.
From Route 9 West Brattleboro, take Sunset Lake Rd right 5.6 miles to the turnoff left at the colorful Manitou wooden sign at ground level.
Parking is plentiful—look for the open area to the left with kiosk.