Welcome to Mary Lake!

Mary Lake is a 154-acre drainage lake straddling Langlade and Oconto Counties, is bordered to the SW, West and NW by the Chequamegon-Nicolet National Forest, and is a headwater for the Oconto River via Mary Creek.  It has a sand and marl bottom with a reported maximum depth of 20 feet, although recent bathymetry reports are showing 10 feet maximum. Due to its shallow nature, Mary Lake is at all times a NO-WAKE lake.  Visitors have access to the lake from an unimproved public boat landing located at the end of Forest Road 2357. There is also a for-a-fee launch managed by Mary Lake P&R District, accessible from Mary Lake Lane. Fish include panfish and largemouth bass. 

Mary Lake has been monitored by volunteers since 1989.  The average summer trophic state for the last 5 years was 47 (Mesotrophic), determined using chlorophyll data. For a Shallow Headwater lake, this is considered Excellent (DNR).  The overall water clarity is listed as clear to moderately clear.  Invasive species at this time are limited to mystery snails and non-native phragmites.