Indian Island County Park is a 275-acre facility located at the estuarine mouth of the Peconic River in Riverhead, featuring access to the Peconic Blueway Paddling Trail (a 9.

5-mile kayak route) and a causeway-connected "island" with picnic areas and waterfront trails.

The park offers daily parking ($7 for residents with green key, $15 for non-residents), camping facilities, and multiple access points for paddling and fishing along the river and Flanders Bay.

Amenities include picnic tables, grills, benches, and hiking trails along the water's edge, making it suitable for both day-use recreation and overnight stays.