The Williamsburg Power Lines and the Unquomonk trail system is all double track. But it does offer a lot of miles of trails. There are a lot of good climbs and long and steep descents (especially on the power lines). Both trails have some mud ( the power lines crosses some swamps) and jumps. I recommend printing out the map posted and bringing a road map in you saddle bag (I use those Western Mass Bicycle maps) because these trails come out all over the place.

The map of the Williamsburg Power Lines and the Unquomonk Trail System (409 KB)

Pictures of the Entrance to Unquomonk

How to get to the base of the Williamsburg Power Lines
Coming from the Northampton. Follow Rt. 9. Past Look Park and Look Restaurant, there will be a fork in the road. Take the left. Follow this road towards the center of Leeds. Take a left onto Reservoir Road at the intersection after the river crossing. Follow Reservoir Road until it merges with Chesterfield Road. Stay on Chesterfield Road through Westhampton and into Chesterfield. Once you get into Chesterfield the pavement is more recently surfaced and is no longer very patchy. Take the first left turn in Chesterfield onto Bofat Hill Road. The left has an island in the middle of the road with a really big tree inside it. If you start going downhill, you have gone too far. 50 yards up the road you'll see the old AT&T site with a good sized greenish/blue shed after the driveway to Chesterfield Products (Black Sign). Park in the parking lot around the shed. Right across the street from the lot is the Power Lines (you can go through the field, the owner doesn't care) and after the field you enter the woods. You can always know if you're on the power lines because there are signs all over the trail that are red/white and say WARNING and say a bunch of stuff about AT&T and don't dig in this area.

How to get to the base of the Williamsburg Power Lines
Coming from Goshen/Cummington/Windsor. Follow Rt. 9 into Williamsburg. Right before the center of Williamsburg, turn right onto Rt. 143. Follow Rt. 143 up into Chesterfield. Take the first left in Chesterfield, Curtis Road, past the Chesterfield Highway Department on the right. Follow Curtis Road until you come to a T intersection. Take the left. At the top of the hill there will be a right turn, Bofat Hill Road. The right has a island in the middle of the road with a really big tree inside it. If you start going downhill, you have gone too far. 50 yards up the road, you'll see the old AT&T site with a good sized greenish/blue shed after the driveway to Chesterfield Products (Black Sign). Park in the parking lot around the shed. Right across the street from the lot is the Power Lines (you can go through the field, the owner doesn't care) and after the field you enter the woods. You can always know if you're on the power lines because there are signs all over the trail that are red/white and say WARNING and say a bunch of stuff about AT&T and don't dig in this area.

How to get to the base of the Unquomonk Trail System
Coming from the Northampton. Follow Rt. 9. Past Look Park and Look Restaurant, there will be a fork in the road. Take the left. Follow this road towards the center of Leeds. Take a left onto Reservoir Road at the intersection after the river crossing. Follow Reservoir Road until it merges with Chesterfield Road. Stay on Chesterfield Road towards Westhampton. You will come to a fork in the road and continue right. After the fork there will be a left turn about half a mile up the road. Don't take that turn but after it there should be a medium sized dirt parking lot on the right directly before a bridge over a brook. At the lot take the trail to the right, the left one that stays close the brook isn't traveled too much, I am not sure where it goes, it might connect to the main trail system but I am not sure.

How to get to the base of the Unquomonk Trail System
Coming from Goshen/Cummington/Windsor. Follow Rt. 9 towards Williamsburg and into it. Right before the center of Williamsburg, turn right onto Rt. 143. Follow Rt. 143 up into Chesterfield. Take the first left in Chesterfield, Curtis Road, past the Chesterfield Highway Department on the right. Follow Curtis Road until you come to a T intersection. Take the left. Follow this road up a hill for a quarter of a mile and then go downhill for about 2.5 miles. If you pass a 3rd right turn, you have gone too far. After the second right turn there will be a good sized downhill, at the bottom there will a medium sized dirt parking lot to the left directly after a bridge over a brook. At the lot take the trail to the right, the left one that stays close the brook isn't traveled too much, I am not sure where it goes, it might connect to the main trail system but I am not sure.