The 2,430-acre area lies in Bridgewater and Northwest townships in the northwest corner of Williams County. Williams County Road R provides access to the area from State Route 576. The area can also be reached by Williams County Road 7 from U.S. Route 20. Lake La Su An Wildlife Area is situated on the Wabash end moraine deposited during the Wisconsin glaciation. Originally, the area was a beech-maple hardwood forest containing beech, white ash, white oak, red oak, and sugar maple. This combination of hardwood species still dominates the area. There are also several lowland areas that are poorly drained, forming wooded wetlands. The wildlife area is moderately to gently sloping with natural drainage to the West Branch of the St. Joseph River, which cuts through the middle of the area. Approximately two-thirds of the wildlife area is in woods and brushland. The other one-third is divided between cropland and meadow. The water areas include 14 lakes and ponds ranging from 1/4 acre to 82 acres, and over 30 wooded wetlands and restored wetlands from two to 18 acres.