Cache River - Cypress Creek Wetlands. 1/11/94; Illinois; 24,281 ha; 37o17’59”N 89o02’18”W. This Site, located at the juncture of four ecological provinces, contains rare examples of forested swamps dominated by bald cypress (Taxodium distichum) and water tupelo (Nyssa aquatica) along the Lower Cache River. The entire Site represents the northernmost extension of the Mississippi Embayment. It is highly biodiverse and supports 103 regionally endangered or threatened species as well as numerous species of waterfowl that feed, rest and nest at the Site. Over 20% of the population of canvasback ducks (Aythya valisineria) pass over the Site, during their autumn and spring migrations on the Mississippi flyway. It also supports over 1% of one of the largest populations of the Illinois Chorus frog (Pseudacris streckeri illinoiensis), and 84 endemic species of fish that make up 44% of the fish documented in the State. Furthermore, flood events in the Cache River basin deliver significant nutrients, organic matter and fish numbers into the larger Ohio and Mississippi river systems. The main threats are associated with the large agricultural areas surrounding the Site and the clearing of land for agriculture. This has led to increased erosion, sedimentation and loss of riparian areas. Site No. 711. Most recent RIS information: 2011.