This singletrack alternative to the fire road through the ski resort can be used as a starting point for the Lenawee
Trail. This isn't the fastest way up the mountain - this trail takes its time winding through shaded forest next to a creek. At some points it follows along near the fire road, and crosses it several times. If you just want the fastest way up the mountain, take the fire road. But I prefer this trail, since it provides a much nicer start to the ride than an access road. On hot days, this trail offers significantly more shade than the fire road.
Park in the main parking lot of A-Basin, by the main lodge. Ride up the fire road behind the Black Mountain Express lift to the first switchback, where the trail begins at a well marked sign post. The trail climbs 1.7 miles up to the Black Mountain Lodge. You'll still have a lot of steep climbing on the fire road from that point to get to the Lenawee
Trail, but at least you had a nice shaded singletrack to start with.