Underhill is within Vermont's 39,837-acre Mt. Mansfield State Forest. On the headwaters of the Brown's River, at about 2,000 feet elevation, the park lies on the west slope of 4,300 feet Mt. Mansfield, the state's highest peak. Just over the summit ridge is the Stowe ski area, one of North America's original ski resorts. <br />
There are four trails to the summit ridge of Mt. Mansfield from Underhill State Park. Walking up the gated road from the park headquarters, the trails begin branching off shortly above the group camp area. The Sunset Ridge Trail, 3 miles to the summit, is the most popular. Vermont's Long Trail traverses the summit ridge and, with several trails from the other side of the mountain, many loops are possible. Hiking information and trail maps are available at the park headquarters.
From I-89 Northbound: Take exit 11 and turn right at W Main ST/ US RT 2. Turn slightly to the right, onto River Rd./ VT Route 117. In about 260', turn right onto Governor Peck Highway and follow to end. At stop sign, turn left onto Browns Trace Road and follow to end (about 5.3 miles). At stop sign turn right onto Route 15 for 1/2 mile. Turn right onto River Road. Continue onto Pleasant Valley Rd (2.7 miles). Turn right onto Mountain Road and follow for 3 miles to end.
http://www.tripleblaze.com/trail.php?c=3&i=5596