Largemouth bass are the dominant black bass species due to the many large pools found in the Maries County portion of the river. Largemouth bass have preference for pools greater that 3' in depth. During spring, largemouth can be found in the backwater off-channel areas, but summer temperatures (prefer water temperatures of 82-87E F) force largemouth into the main channel habitats where the water quality is better. The larger bass defend a territory that gives them the best access to cover and food that may consist of insects, crayfish, frogs, or fish. Sampling by fisheries biologists shows that largemouth are the largest bass species within any pool. Spotted bass look similar to largemouth bass in appearance except for their lower maximum total length and tooth patch on the tongue. Spotted bass can also be caught with some regularity in the Gasconade River by fishing the rootwads and snags associated with current along cut banks.
The Gasconade River watershed is located within the Ozark Plateau of the Interior Ozark Highlands. The river meanders north to northeast through Webster, Texas, Wright, Laclede, Pulaski, Dent, Maries, Osage, Phelps, and Gasconade counties to join the Missouri River. The Gasconade River is 271 miles long from mouth to headwaters with 263 miles having permanent flow. The Upper and Lower Gasconade River watersheds drain 2,806 square miles. Gasconade River game fish species that are commonly fished by the pole-and-line method include smallmouth bass, largemouth bass, rock bass, channel catfish, flathead catfish and crappie species. Panfish species such as longear sunfish and bluegill sunfish are less commonly fished but are a good addition to the creel. Other species of fish such as the sucker and redhorse are taken by gigging or other methods and are excellent fish species for the fish fry. The paddlefish is also sought in reaches of the main stem Gasconade River. Anglers have numerous sport fishing opportunities as the Gasconade River changes character from an Ozark headwater stream system to a large river system. According to the Missouri Department of Health, all game fish are safe to eat in the Gasconade River watershed. Studies on the Osage Fork of the Gasconade River revealed that numbers of black basses and rock bass of regulation size were in good supply.
The Gasconade River is a tributary of the Missouri River, about 265 mi (425 km) long, in south-central and central Missouri in the United States.