Umstead's bike & bridle trail is the core of the Umstead 100, one of the most popular ultra trail runs in the country. The race is popular because the tread is a foot-friendly, finely crushed gravel surface that stands up well to miles of food-pounding. Because it's double-track, it's also a popular site for group runs as well us for a couple of buddies who like to train together and make the miles pass faster as they catch up. Umstead has two main entrances - off I-40 at Harrison Avenue and off U.S. 70/Glenwood Avenue - but the most popular entrance for runners is the neighborhood entrance at Lake Crabtree on Old Reedy Creek Road. Park near the bridge, warm-up with a gentle half-mile climb to the park gate on a gravel road. From the gate to the gate at the far end of the park is 5 miles - a 10-mile out and back. The two miles or so is relatively flat; after that, it's a series of long climbs. For exceptional hill work throw the Turkey Creek Trail into the mix. Not much flat here, especially on the North Turkey Creek leg, which features a number of short, steep climbs. The bike & bridle trail meshes well with the 20-mile network of singletrack, making the centrally-located Umstead a prime destination for the Triangle's trail running community. More info here. Maps: Downloadable map available here, free map available at trailhead. Getting there from downtown Raleigh, here.