O'Leno State Park is located on the banks of the Santa Fe River, a tributary of the Suwannee River. The park was developed by the Civilian Conservation Corps back in the 1930's and is one of Florida's first state parks. Originally, the park was opened in 1938 as a Florida Forest Service training camp but after two years in operation, it was transferred from the State Forestry office to the State Parks office. Featured on the property are sandhills, hardwood hammocks, river swamps and sinkholes. Also on the property: the sinkhole where the Santa Fe River disappears into the limestone underground to reappear three miles away in the adjacent River Rise Preserve State Park.

O'Leno State Park offers hiking, biking, horseback riding trails, camping, fishing, canoeing, kayaking, swimming, picnicking and wildlife watching. There are two campground loops with a total of 61 campsites, each with picnic table, grill, water and electric. Each loop also has a centrally located restroom. There are universally accessible bathroom facilities in both campground loops. Maximum RV length: 50 feet. Primitive camping is allowed at the Sweetwater Lake Camping Area, a walk-in facility about 6.5 miles from the nearest parking area. There is a fire circle and privy there but little else. The campground will accommodate up to 10 people. Equestrian camping is available nearby at River Rise Preserve State Park.

O'Leno State Park offers more than 15 miles of marked and maintained hiking trails, including one that leads to the place where the Santa Fe River sinks into the ground. In some areas, you might come across alligators and turtles in the water. Swimming is allowed in a designated area on the Santa Fe River but there are no lifeguards. There are children's playgrounds in the picnic area and at the Magnolia camping area.

For day use, O'Leno State Park is open from 8 am to sunset every day of the year. Admission fees: $5 per vehicle for two to eight occupants. $4 per single occupant vehicle. $2 per pedestrian, bicyclist and extra passenger. Camping fees: $18 per site per night (plus tax), includes electric and water. Primitive Camping: $5 per person per night (plus tax). Youth Camping: $1 per youth per night (plus tax), organized groups only (scouts, church, etc.) $5 per adult chaperone per night (plus tax). Picnic Pavilions: $15 per day (plus tax) for smaller pavilions. $50 per day (plus tax) for larger pavilion. Cabins: From May through August, all 16 cabins must be rented together as one group: $300 per night (plus tax), includes the dining and recreation halls. September through April the cabin rentals vary from $25 to $150 per night (plus tax) depending on the cabin. The cabins are neither heated nor air conditioned. O'Leno State Park is located about six miles north of High Springs on US Highway 441.