Galveston Island State Park is on Farm Road 3005 six miles southwest of Galveston in southwest Galveston County. The park spans the width of Galveston Island and has four distinct ecological zones: salt marsh, coastal prairie, sand dunes/maritime wetlands, and sandy beach. The Park's boundaries also include two miles of beach on the Gulf of Mexico and frontage on West Galveston Bay.

The 1,921-acre site was previously Maco Stewart's cattle ranch. There are still remnants in the park that attest to its "cattle days". A windmill stand and watering trough as well as a cattle dipping vat which was used in the efforts to control the spread of Texas Cattle Tick Fever.