William B. Umstead State Park is a North Carolina state park in Wake County, North Carolina in the United States. It covers 5,599 acres (22.66 km2) nestled between the expanding cities of Raleigh, Cary, and Durham, North Carolina. It offers hiking, bridle, and bike trails, boat rentals, camping, picnic areas, and educational programs. Umstead is bordered by Raleigh-Durham International Airport on the west, Interstate 40 on the south, US 70 on the north, and by the western outskirts of Raleigh on the east. The main bridle and bike trail is Reedy Creek Road, which is open to traffic in western Raleigh (connecting the North Carolina Museum of Art to the park entrance), closed except to rangers' vehicles as it crosses the park from east to west (a distance of 3.5 miles), and then heads south into Cary where it becomes open to traffic again. At the edge of the park it connects to Black Creek Greenway and the Lake Crabtree County Park trails. Crabtree Creek also flows across Umstead, its source is Lake Crabtree right at the park's edge, and it flows eastward throughout much of the southern part of the park (with trails in varying degrees of maintenance along its length) and then crosses Reedy Creek Road to flow north. The main entrances are the two ends of Reedy Creek Road, two entrances off of Ebenezer Church Road in Raleigh near where Crabtree Creek leaves the park, the official Reedy Creek entrance at the end of Cary's Harrison Avenue, and the park's main entrance at Highway 70 in the north. The latter are equipped with parking lots, bathrooms, and campgrounds, at the Highway 70 entrance there is also a visitors' center and a campground. Other important bike and bridle trails include Graylyn Road, connecting the Ebenezer Church entrance to Reedy Creek Road, and Turkey Creek Road, which winds through the northern part of the park, hiking trails include the Company Mill trail in the south and the Sycamore Trail in the north, both of which are loops of moderate difficulty, as well as many others. Bikes and horses are prohibited on hiking trails.