Forbes Forest is 59,000 acres comprising Westmoreland, Fayette, and Somerset Counties. It was named after General John Forbes who ordered the Forbes Road to be built from Bedford to Fort Pitt so the British could attack the French Fort Duquesne in 1758. There are over 250 miles to use for hiking and mountain biking. You can horseback ride on many trails but make sure to refer to their webpage for more information. Forbes Forest also offers a few designated picnicking areas as well as streams to fish and plenty of land to hunt.
Check out their website for more information on designated recreational areas before partaking in any activities.