Ducks Unlimited conserved its first acre of water in 1938 on Big Grass Marsh, just north of Gladstone, Manitoba. The Marsh was origionally a sprawling wetland complex spanning 100,000 acres (40,500 ha), but between 1909 and 1916 it was drained for agriculture. Instead of yielding the fertile fields that locals had envisioned, Big Grass soon became a desolate tract of dust and silt. When Engineer Bill Campbell arrived to restore the marsh in 1938, a grateful community praised Ducks Unlimited's restoration work.
Today, Big Grass Marsh is a 12,400 acre (5,000 ha) complex, half of which is Crown Land and the remainder owned by the Municipality of WestLake-Gladstone. The Northern Zone consists of 220 quarter sections of land north of Provincial Road #265, and the Southern Zone has 227 quarter sections of land south of Provincial Road #265.
Big Grass Marsh is an Important Bird Area of Canada. It is an important moulting and staging area for waterfowl including Mallards, Snow Geese and Canada Geese. The site also has globally significant numbers of nesting Franklin's Gulls. During fall migration, the number of Mallard Ducks in the area have exceed 10,000 birds. As many as 6,500 migrating Sandhill Cranes have been recorded in the northern portion of Big Grass Marsh, around the Jackfish Lake region.
More information about the significance of the Big Grass Marsh to migratory birds and other wildlife can be found at the Important Bird Areas of Canada (IBA) website. More specific information about the significance of Big Grass Marsh as an Important Bird Area of Canada can be found at the IBC Canada site summary for Langruth