The best way to eliminate skunks is to remove what they like. So get rid of piles of lumber, wood, and junk, store trash in tightly sealed containers, and don't leave pet food outdoors. Installing fencing to a depth of 1-2 feet below the ground and sealing foundation openings will prevent skunks from denning beneath a house.
But if a skunk is already there, put large amounts of mothballs into old socks or cloth bags, soak rags in ammonia, or take clothing with a strong human scent and place any or all of these beneath the building. (Attach string to the materials for easy removal.) To determine whether the skunk has left, sprinkle flour at the entrance to the foundation opening to mark the direction of the tracks. Skunks are nocturnal, so check the area for tracks a couple of hours after dark. Once the skunk is gone, seal the entrance to prevent re-entry.
For additional information on dealing with skunks, contact your local animal control officer, a commercial pest-control enterprise, or the Colorado State University Cooperative Extension at www.ext.colostate.edu. For regulations regarding trapping, shooting, and other skunk-control methods, visit the Colorado Division of Wildlife site at www.wildlife.state.co.us. --L.L.