A trout stamp is an extra endorsement or permit on a fishing license needed in some states to fish for trout. You might be wondering, but why an extra purchase just to fish for trout? Shouldn't it be included in the base license? The answer to that is trout hatcheries and put & take fisheries.
A put-and-take fishery is where someone stocks fish in a place where fish are not able to spawn and live out full lifecycles in the wild. Instead, they are stocked with the intention of anglers catching them and taking them home to eat. In some places, the water can get so warm or oxygen deprived at points in the year that the trout are unable to even survive one full year. Therefore, the trout need to be constantly raised in trout hatcheries and stocked on a frequent basis so there will be fish to catch. With the cost of raising and stocking the fish being variable to the number of anglers participating, it makes sense they should be the ones to pay for it.
Anglers who have trout stamps are often surveyed by the fishing authority to ensure appropriate trout stocking levels. Buying a trout stamp not only allows the angler to fish for trout but have a small voice in the distribution of the trout.
Freshwater Fishing