The San Juan earth worm got its name from the famed trout river in New Mexico, the San Juan River. This pattern simply enough imitates earth worms very effectively. The San Juan earth worm can be used as a great attractor pattern that catches fish all year long. Often times, anglers will tie on a San Juan earth room if it had rained the day before, when there are more worms in the river. The San Juan Earth worm if effectively fished in a nymph or dry dropper rig.