What's a good way to get rid of moles under a lawn?

Moles are hard at work tearing up my lawn. Smoke bombs had a good effect for a couple of years until last year when smoke bombs had no effect. The only thing that stopped the moles last year was a Northwestern Garter snake that put down one mole holes. I haven’t been able to capture any garter snakes this year yet so here I sit watching my yard being destroyed by the little rodents. I’m thinking about dropping a fire cracker down a mole hole and quickly covering it with the bottom of a trash can hoping that the concussion will either kill or chase the moles away from my yard. Do you have any good ideas?