Lake Onalaska

Pool 7’s recreational use is among one of the highest of the Upper Mississippi River Pools. The dominant feature of this area is Lake Onalaska, famous throughout the Midwest for its fishing, boating and waterfowl hunting resources. The lake is a large 7,700 acres of backwater with a divers population of fish and waterfowl. The nearest bridge crossing, I-90 is immediately downstream of Lock and Dam 7. Approximately 65% of Pool 7 is classified as backwater.

Gizzard shad are the most prevalent species found. Other species include silver chub, speckled chub, emerald shiner, river shiner, spotfin shiner, juvenile panfish, carp, and bullhead.

Walleye begin to concentrate below the dam during the late winter months until ice out in March. As the water temperature rises into the 40’s, walleye move upstream from winter areas into backwater areas for spawning. Spawning takes place when the temperature is between 47-51 degrees, which is usually in April. White bass concentrate below dams and spillways as the walleye run ends, usually ends by in late April. Most largemouth are found in backwaters until mid-June since these are the first areas to warm. When the backwaters warm these fish move to side channels and main channel edges where they can be found along riprap. Some of the largemouth spend summer in tributary streams. When the water cools bass move to low-current areas in or near backwater complexes. Northern Pike share the same seasonal movement as largemouth bass.