Mark Twain Lake Overlook Trail is a standout hiking destination in Monroe City, MO, covering 6.0 miles with 400ft of elevation change. Stats: 6.0 miles, 400ft gain, Moderate. Type: Loop. Surface: Dirt. Time: 3 hours. Fee: Free. Dogs: Yes, on leash. Permit: No. Wildlife: deer, eagles, herons. Best seasons: Missouri River tributary reservoir. Pack water, layers, and appropriate footwear. Conditions vary across MO. Leave No Trace: stay on trail, pack out all waste, respect wildlife.