Blackwater Lake: Six miles south of Longville at the intersection of Cass County Road 11 and MN Hwy 84 is beautiful Blackwater Lake. The clear 722 acre lake sports Bass, Northern Pike, Walleye, Small Mouth Bass, Bluegills and Crappies. Lakes Lake Maps Home Big Sand Lake Blackwater Lake Boy Lake Girl Lake Lake Inguadona Leech Lake Little Boy Lake Long Lake Pleasant Lake Thunder Lake Wabedo Lake Woman Lake