Leg press, deadlifts, RDLs, lunges, leg extensions, leg curls, hack squats, split squats. All those will hit your legs, plus there variations. Do some sprints, run hills, stairs, those will hit your legs. Im sure there are more lifts I can't think of this second as well.
While natural gas occurs in nature as a mixture of methane and other gases, propane is actually a byproduct of both petroleum refining and natural gas processing.
Natural gas grills are less expensive than propane or charcoal, but they require the installation of natural gas line from the house to the grill, and and therefore cannot be moved. Dual fuel gas grills allow you to easily cook with either liquid propane or natural gas.