The San Juan Worm is a simple yet incredibly effective pattern that imitates aquatic worms - an often overlooked but abundant food source for trout. useful year-round and effective in a wide range of water types, it's especially productive in off-color or high-water conditions. Typically fished as a dropper or trailing nymph near the bottom, the San Juan Worm is a great choice when visibility is low or fish are feeding on larger subsurface prey.