On a hot summer day in 1916, Dr. S.M. Sewell, a mathematics professor, decided that the university needed a park, with an area to swim. Back then, the river was only three feet deep. In 1917, the U.S. Bureau of Fisheries leased the college four acres of land along the river. College students, armed with mud scrapers and mules, cleaned the river bottom, built up the banks and smoothed the slopes. It was called Riverside Park until 1946, when it was renamed in honor of its founder, Sewell.
The park's current look is the result of a $1 million renovation in 1984. Sewell is now a favorite student hangout on campus. The six-acre park features grassy banks for soaking up sun, playing Frisbee with friends, a basketball court, volleyball courts, and picnic and barbecue areas — all along the riverbank. Stairs provide easy access for swimming or snorkeling in the San Marcos River. With the Outdoors Center nearby, students, staff, and alumni can rent out kayaks, paddleboards, and other water equipment to use in the river.