The image at left shows a Stamp-associated sign – "Your Duck Stamp Dollars At Work" – at an emergent marsh at the Pondicherry Division of the Silvio O. Conte National Fish and Wildife Refuge in Jefferson, New Hampshire. (You can see Cherry Mountain in the background, part of the White Mountain National Forest.) Almost 30 percent of the Pondicherry Division has been acquired through Migratory Bird Conservation Fund (MBCF) dollars. The MBCF is where Stamp dollars are held prior to investment.
You can access an invaluable listing of every National Wildlife Refuge that has received funding through Stamp dollars here (updated as of April 2016). This involves 252 refuges in the lower 48 states.
Another way to look at the data is via the following interactive map of refuges across the country, prepared by the Cornell Laboratory of Ornithology. The map is color-coded according to the percentage of land in each that was acquired with Duck Stamp/MBCF money.