Snake control can best be accomplished by depriving the snakes of the things they need to live. This includes harborage(a place to live and hide), food and water. In other words by keeping the weeds mowed around the building and keeping the rodent population at zero pretty well eliminates snakes in a residential area. But there are a number of ways to repel and trap snakes of all sizes.
Dr.T's Snake-A-Way is a granular product that the snakes smell with their tongue. This irritates them and they move in the opposite direction.
Snake-a-way is very repulsive to most snakes. Just a whiff of this product and they go the other way. Dr. T's will last up to 3 months outside in normal weather. A 4# container will treat the perimeter of a 1/4 acre lot.
It can be used to protect gardens, tree houses, well houses, sheds, barns, etc.
It works really well as a perimeter around a camp site. I know of several people who back pack this in and sprinkle it around their tent at night before sleeping.
Glue boards can also be used to catch snakes. For small snakes and lizards the mouse size glue board is all that you need. For very large snakes try theSnake Guard Glue Board. This will catch the largest rattler. To release the snakes unharmed from the glue boards massage some cooking oil into the glue holding the snake and than remove the glue and oil from the snake with an oiled cloth.
Some combination of the above products and methods will prove effective in controlling all snakes, including copperhead, cottonmouth, garden, rattle and water snakes.