Howell Island Conservation Area protected area covering 2,547 acres (10.31 km2) and managed by the Missouri Department of Conservation on Howell Island located in the Missouri River in Boone Township, St. Charles County, Missouri, although the MDOC land surrounding the parking area is in St. Louis County.

The island is bounded by the Missouri River on the north side and Centaur Chute to the south.

[1] The island was named for either Thomas or John Howell, who were early settlers in the area.

When the river is about 16 feet (4.9 m) at the St. Charles gauge (about 17.8 miles downstream), the Centaur causeway, which provides land access, is flooded.

[1] Fishing is permitted in the Missouri River, which borders the north side of the island for 5 miles (8.0 km), as well as the Centaur Chute.