Monroe Lake is an Indiana State Park located southeast of Bloomington, Indiana. The reservoir area is situated in Mississippian bedrock, almost entirely from the Edwardsville Formation of the Borden Group. An impressive crinoid bioherm is exposed on the peninsula of Allens Creek State Recreation Area (no collecting allowed). Geodes are exposed at multiple locations around the lake property, but they may be collected (small quantities for personal use only) only on Hoosier National Forest property. The Mt. Carmel Fault cuts north-south across the lake near Cutright State Recreation Area; both the Mt. Carmel and Heltonville Faults are exposed at the surface in the Frog Pond Ridge area of the Hoosier National Forest just south of the lake where they have formed a graben. Although collecting material is prohibited on most public land around Monroe Lake, there is a designated collection pile located inside Paynetown State Recreation Area.
4850 South State Rd. 446
Bloomington, IN 47401