How do i get rid of gophers / moles?

I'm gopher batty! How do i get rid of them?! I have 2 acres ( just lawn...no garden) split between trees. I'm not worried about the back acre, but the front is where they seem to be anyway. I've seen numerous raised "trails" all around, and i've tried those bait pellets that come in a plastic cone-shaped bottle (you use the tip of the cone to pierce the trail and drop a tsp of pellets in), but THAT doesn't seem to work. Now i've seen a few actual Mounds just off my front porch! - never saw mounds before! ..just trails / tunnels. What can i do?