You can purchase "Fish Decoys" from various shops through out the North Woods and the Upper Pennisulia Michigan, also through some of the web sites on the Resources page.
If you are looking for specifically Native American "Fish Decoys" made by Smithsonian Institute artists, Ross "Little Ross" Allen, Jr, John "Little John" Cross, John V. Snow, and Kenneth "Buddy" Wayman then you should check out a shop called The Homestead in Boulder Junction, Wisconsin. The Homestead is located outside of town near the north east corner of County M and Fish Trap Road. The Homestead has the largest inventory of Native American "Fish Decoys" available. The owner/operator is also very knowledgeable and informative.