Fishing Union Lake

Union Lake's Largemouth Bass fishery is exceptional, drawing 15.6 tournaments per year with good catch rates of 1.8 legal bass per angler. Growth rates run above state average (+0.8 growth index) with fish reaching 19 inches. Smallmouth Bass provide a bonus fishery uncommon in southern Michigan inland lakes, benefiting from the Saint Joseph River connection that offers thermal refuge and additional forage. The Bluegill population shows excellent size structure with good numbers of 7-8 inch preferred fish, though dominated by a massive 2020 year class of 1-2 inch fish comprising 70% of the catch. Black Crappies run low in density but excellent in quality, with 29% over 10 inches and dominated by 11-inch fish from a strong year class. Strong 2020 recruitment suggests the crappie fishing will improve as these fish grow. Yellow Perch average 8.2 inches with 14% over 10 inches, providing steady action. The lake's shallow 16-foot maximum depth and connection to the Saint Joseph River creates unique habitat. Substrate is primarily sand and organic material with scattered stumps providing critical structure, especially after vegetation declined in the 1980s. Wood habitat additions in 2020 helped offset stump removal from the 2018 drawdown. The 544-acre impoundment behind Riley Dam offers diverse structure from shallow depositional areas upstream to deeper water near the dam. Northern Pike reach impressive sizes up to 36 inches but remain sparse. Channel Catfish produce trophy fish with Master Angler entries up to 10.38 pounds reported. Walleye stocking has been discontinued due to poor habitat - only two fish captured despite decades of stocking efforts. The lake's location downstream of Coldwater and Upper Saint Joseph River confluence provides excellent forage base supporting the quality predator growth.