Maplewood State Park occupies hills near the eastern edge of the Red River Valley that were deposited as part of the Alexandria Moraine during the last ice age, creating abrupt relief, deep valleys, clear lakes, and wetland basins. Lake Lida, the park's largest lake, likely formed when the last glacier retreated 20,000 years ago, leaving stranded ice in a valley that later melted and exposed the basin. The idea for a park there was proposed in 1923, and through the efforts of the Maplewood State Park Association the park was established in 1963 to protect unique natural and cultural resources, beginning with a little over nine sections of approximately 5,600 acres. Most land acquisition took place in the 1960s and 1970s, and the park now covers about 9,250 acres. Glacial periods also formed most of Maplewood's wetlands, and although many original wetlands were drained for farming, more than 50 have been restored, providing wildlife habitat, filtering pollutants, and reducing flooding. The park contains eight major lakes and many ponds, supports game fish populations, and offers fishing, boating, canoeing, swimming, picnicking, camping, hiking, horseback riding, snowmobiling, and skiing. It is known for spectacular fall colors, spring and late-season flowers from both prairie and forest environments, and abundant wildlife including more than 150 breeding bird species, 40 mammal species, 25 reptile and amphibian species, and a stop on the Pine to Prairie International Birding Trail, where species from prairie and forest ecosystems mingle along the transition zone.