Near Martin, Lacreek National Wildlife Refuge (NWR) was established in 1935 as a Refuge and breeding ground for migratory birds and other wildlife. The Refuge lies in the shallow Lake Creek valley on the northern edge of the Nebraska Sandhills and includes 16,410 acres of native sandhills, sub-irrigated meadows, impounded fresh water marshes, and tall and mixed grass prairie uplands.

It is the home of the High Plains trumpeter swan population, which now totals more than 450 birds. The Refuge hosts one of only two nesting colonies of American white pelicans (approximately 3,000 birds) within South Dakota. The Refuge serves as an important staging area for migrating Canada geese, other waterfowl, sandhill cranes, shorebirds, and neotropical migrants. Black-tailed prairie dogs and burrowing owls are common in the uplands, and bald eagles are frequent winter visitors.