Letchworth State Park was founded by philanthropist William Pryor Letchworth in 1907, when he donated his 1,000-acre estate to become a park. Today, the park has grown to more than 14,500 acres, extends 17 miles, and surrounds and protects the three canyons of the Genesee River. Known as the Grand Canyon of the East, it features lush forests, gorge cliffs that drop nearly 600 feet to the Genesee River's rapids, and a 107-foot waterfall at Glen Iris Inn. The park also preserves the region's heritage through associations with Mary Jemison, the William Pryor Letchworth Museum, the Council Grounds, a Civil War monument, the area's geological history, and the Mt. Morris Dam built by the U.S. Army Corp of Engineers.