Cowboy can't get around like he used to, so when the spring ramps sprout, he asks Spencer and Eugene to build him an all-terrain four-wheeler that will take him to his favorite ramp patches no matter how steep the spot they grow, up on Cold Mountain.

When a dying hemlock tree threatens to topple over onto Spencer's forge, Eugene makes a plan for bringing the giant tree down safely, and then for using the 500-pound logs to build a valuable drying shed that will help Spencer grow his herb business.

When Spencer hears that the fire chief wants to equip his squad with Cold Mountain-made tools, he and Eugene salvage a steel saw blade from the big scrapyard, and get to work forging a bushwhacking brush clearing machete from it, to win the contract.

Spencer and Eugene mount an old camper onto barrels that they weld together to make their own hillbilly houseboat. But when they attach a lawnmower-powered paddlewheel and take it to the lake, will the boys and their latest contraption sink or swim?

A heat wave is causing meltdowns on Cold Mountain. Eugene and Spencer build an air conditioner, for Mama Gene's car, from an old fan and wet rags. But when they use deadly materials to build a house-sized chiller, will it all blow up in their faces?