Trapping gophers is one way to get rid of them in your yard. Look up different types of traps in books or online. Build or buy a trap that suits your needs.
Buy fencing that has small holes, like chicken wire for example. Start by digging a trench around the area that you don't want the gophers in. Dig the trench about two feet deep. Insert the bottom of the fencing along with the supports. Bury the bottom part of the fence to prevent the animals from burrowing underneath.
Flooding the gopher tunnel system takes quite a bit of water, but if it gets rid of the gophers it's worth the effort. Find a gopher hole and insert a garden hose as deep as you can get it. Turn on the water and let it run for 15 to 30 minutes to flood the gophers out of their home.
Plant some Caper Spurge. The roots and the seeds of the plants are toxic. The gophers eat these plants and then die. Be careful, though as these plants can cause harm to humans and other animals as well. If you touch the sap of one of these plants, it will cause irritation. Wash your hands thoroughly after handling Caper Spurge.
Clog Their Intestines
Some people have found success in ridding their yards and gardens of gophers by clogging up the animals' intestines. There are two ways to do this. Go to your local barber shop and ask if you can collect some of the cut hair. Place the hair into the gopher holes. The gophers eat the hair and it gets stuck in their intestines.
Another way to clog their intestines is by placing a piece of gum in the hole. Wrigley's spearmint or peppermint seems to be the favorite choice. Unwrap the gum, but do not touch it with you fingers at all. Place the gum as far down into the hole as you can get it. The gophers will eat the gum, but it will get stuck in their intestines and cause them to die.