The longest hiking trail in the state is the 223-mile Ouachita National Recreation Trail which extends from Pinnacle Mt. St. Pk. west of Little Rock..across the Ouachita National Forest and ends at Talihinia, Oklahoma. It's called the Ouartz Crystal Capital of the world - Mt. Ida in west Arkansas. The only other two places in the world containing quartz crystals are Madagascar and Brazil. Other than by boat, the other adventurous way to enjoy Lake Ouachita is by taking a trail ride on horseback along the scenic vista shoreline. The Louisiana Purchase Historic St. Pk. Marks the initial spot in a swamp in east Arkansas where land surveys began in 1815 for the Louisiana Purchase Territory.