You searched for: Institution University of Michigan. Libraries Remove constraint Institution: University of Michigan. Libraries Place Grattan Twp., ca. 3 mi. east of Cannonsburg on 6 Mile Rd., and ½ mi. north on gravel road/driveway. Saul Lake Bog Preserve on Saul Lake. Remove constraint Place: Grattan Twp., ca. 3 mi. east of Cannonsburg on 6 Mile Rd., and ½ mi. north on gravel road/driveway. Saul Lake Bog Preserve on Saul Lake.