In Grand Teton National Park, anglers 14 years old and older must purchase a Wyoming fishing license (link below). The license is valid for fishing within Grand Teton National Park and on public waters outside the park in Wyoming (not in Yellowstone National Park or the Wind River Indian Reservation).
In Yellowstone National Park, anglers 16 years old and older must purchase a fishing permit from the National Park Service (link below). The Wyoming Game and Fish Department does not sell park service licenses nor manage fisheries within Yellowstone National Park. National Park fishing permits are not valid outside of the park boundaries.
On the Wind River Indian Reservation, permits are required for fishing (link below). Game and Fish does not sell reservation permits nor manage fisheries on reservation lands. Reservation permits are not valid beyond the boundaries of the reservation.
Grand Teton - Wyoming Fishing License
Yellowstone National Park Fishing
Wind River Indian Reservation Fishing