Richland County is on the west side of Charles Mill Lake. Ashland County is on the east side of Charles Mill Lake. If you carefully keep your bird records by county, be sure to use the specific hotspots on this lake so that the birds will be assigned to the proper county.
Charles Mill Lake is located on the Richland-Ashland County line, on OH-603 off US-30, approximately 1 mile west of Mifflin. There are two boat ramps both off OH-430. The marina is located by the boat ramp on the eastern basin of the reservoir.
The Muskingum Watershed Conservancy District owns Charles Mill Lake. The reservoir was constructed in 1935 by damming the Black Fork of the Mohican River. The reservoir impounds 1,350 acres of water and has 25 miles of shoreline. The main purpose of constructing the reservoir was flood control. The watershed draining into Charles Mill covers 5,040,002 acres. Today, recreation is one of the biggest public benefits of the reservoir. The ODNR, Division of Wildlife manages the reservoir to provide public fishing and hunting opportunities.
The Black Fork of the Mohican River flows into the north end of the reservoir and flows out over the dam on the south end of the reservoir. The reservoir is divided up into three basins: one north of OH-430, the second south of OH-430, and the third to the east of the second basin. The basin north of OH-430 is very shallow. Channels to the boat ramp in this basin are kept open by dredging. This north basin is frequently very turbid. The basin south of OH-430 is again relatively shallow; most of the southern basin is around 6 feet deep. The narrow passage leading from the southern basin to the eastern basin is about 15 feet deep. The eastern basin is the deepest part of the reservoir with several deep holes including a hole 27 feet deep. The eastern basin generally has the clearest water in the reservoir.
There are restrooms in the day-use area below the dam (closed in the winter). Campgrounds have restrooms for campers.