- The refuge includes native sandhills, sub-irrigated meadows, impounded fresh water marshes, and short-grass prairie uplands. This is the region where the transition of eastern and western flora and fauna occurs. The wildlife concentration include a wide variety of life forms from aquatic and marsh dwelling species to fauna typical of the short grass prairie.
Endangered or threatened species include: the bald eagle, peregrine falcon and whooping crane. The burrowing owl, merlin, osprey and ferruginous hawk, listed as threatened or endangered by the State of South Dakota, are also sighted occasionally on the Refuge.
The most sought after species on the refuge is the trumpeter swan. The Lacreek swan flock originated from cygnets obtained from Red Rock Lakes NWR, in Montana in the early 1960's. Pioneering trumpeters now nest in both South Dakota and Nebraska, with approximately 250 birds returning to Lacreek each fall to spend the winter. In 1994 it was discovered that trumpeter swans that nest in eastern Saskatchewan also winter at Lacreek Refuge. Average annual refuge production includes 15-20 trumpeter swans, 2,000-6,000 ducks, and 500-800 Canada geese. Spring concentrations of 14,000 ducks and geese and fall concentrations of 22,000 are not uncommon.
Lacreek refuge is located in southwestern South Dakota in the shallow Lake Creek Valley on the northern edge of the Nebraska Sandhills.