The Creston Valley Wildlife Management Area covers 7,000 hectares (17,000 acres) of provincial land, or an area that averages 20 km (12.4) miles long by 3.4 km (2.1 miles) wide. It consists of one lake (1,500 ha or 3,700 acres) and 17 marshes plus a major river and adjoining mountain slopes.  The marshes form a valuable link in a chain of wetlands stretching from the Arctic Ocean to California.

The CVWMA is located south of Kootenay Lake and extends south to the Canada/US Border and is nestled between the Selkirk and Purcell mountain ranges.  The area encompasses a substantial part of the Kootenay River floodplain and consists of dyked marshland, lakes, sloughs, agricultural fields and adjacent river terraces.  The CVWMA is located within a very dry warm variant of the Interior Cedar-Hemlock biogeoclimatic subzone and experiences very hot and dry summers and mild winters with light snowfall.  These climatic conditions combined with the wetland and riparian habitat make the Creston Valley a critical breeding, staging and wintering area for a broad diversity of wildlife species.

The CVWMA is currently comprised of approximately equal portions of open water, wetland habitats (including permanent and seasonal wetlands) and upland habitats (grasslands, shrublands and forest).  With the exception of the forest habitat types, the habitat types (permanent and seasonal wetland, lake and open water, rivers and wide channels, upland grass areas, upland shrub) were either extremely rare or non existent in the Creston Valley prior to the creation of the CVWMA and the subsequent construction of dykes and water control structures.