Pool 11 of the Upper Mississippi River extends 32.1 miles from Lock and Dam 11 in Dubuque to Lock and Dam 10 in Guttenberg. Pool 11 contains 19,875 acres of aquatic habitat. The upper and middle portions of the pool contain many islands, side channels, and backwaters while the lower pool is a broad expanse of open water. Pool 11 encompasses the majority of the natural river floodplain and is bounded by limestone bluffs. Major tributaries that enter the Mississippi River in Pool 11 are the Turkey and Little Maquoketa Rivers in Iowa and the Grant and Platte Rivers in Wisconsin. Pool 11 is also part of the Upper Mississippi River National Wildlife and Fish Refuge.