This is the way to reach Hazel Mountain from outside the park. It is also shorter than the White Rocks-Hazel Mountain route. Although it is steeper overall, it does not have the ups and downs of that other route. It does, however, involve four stream crossings. During periods of heavy runoff, these crossings can be tricky or dangerous. If the scrambling and bushwhacking to the summit do not appeal to you, this route still makes a very nice hike, especially in spring and fall.
The route is a loop and can therefore be done either way, but the lower half of Sam's Ridge Trail is very steep, so hikers and climbers may prefer to follow the route the way I describe it.
To access the peak from outside the park, drive to Sperryville (about 10 miles east of Skyline Drive's Thornton Gap Entrance along U.S. 211) and follow signs to U.S. 522 and SR 231. Drive south on 231 for about three miles and then turn right onto SR 831. Then turn right onto SR 600 and drive to a bridged crossing of Hazel River. There is room here for 2-4 cars to park off the roadway (obey posted signs about private property). Hike west along the private road (open to foot traffic) paralleling Hazel River for 0.2 mi, where the park trails actually begin. The distance from 231 to the parking area is 2 miles. If approaching from the south, make sure you are looking to turn left onto 831.
According to my guidebook, this loop, without the side trip to the summit of Hazel Mountain, is 5.8 miles. Add about another mile RT to include the summit.
These are according to my guidebook.
Start-- Trailhead (950'). Hike up the road and make sure to stay on it.
0.4 mi-- Shortly after passing the signpost for Sam's Ridge Trail, you reach the signpost for Hazel River Trail.
1.6 mi, 1481'-- Junction with White Rocks Trail. Bear left to stay on Hazel River Trail.
To reach the summit, leave the Hazel River Trail at some point and start heading up. As the trail climbs, it follows a tributary of Hazel River that is between the summit and the trail. Eventually, you reach the head of this drainage and you can head for the summit slopes without giving up elevation. This is also the best way to access a boulder-strewn slope that leads almost all the way to the summit ridge and is relatively free of underbrush. The trip up these boulders never gets harder than very easy Class 3, though it can be harder in wet or icy conditions, of course. When you reach the summit ridge this way, head south along the path of least resistance until you reach the highest point.
The summit is less than half a mile from Hazel River Trail. Elevation gain from the trail varies depending on where one leaves the trail, and it ranges from approximately 500-1400'.
Hike downhill west, south, or somewhere in between until you rejoin the trail. I wound up just a few yards away from the junction of Hazel River Trail and Hazel Mountain Trail. From the junction, it is 0.2 mi along Hazel Mountain Trail to its intersection with Sam's Ridge Trail, which is coincident with Broad Hollow Trail for 0.2 mi. The distance back to the parking area via Sam's Ridge Trail is 2.2 mi.
If you are only hiking the trails, just dress for the day's weather and consider having trekking poles or a walking stick to help with the crossing of Hazel River.
People heading for the summit should wear pants, not shorts, no matter what season it is (or else thorns will make you an unwilling blood donor, and poison ivy may pay a not-so-nice visit), and probably long sleeves as well (this underscores why it is not a good idea to climb this peak during the warmer months).