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.
Propane vs. natural gas cost comparison. If the natural gas cost is $15.00 per 1,000 cubic feet, the same $15.00 will purchase around one million BTUs, this is the equivalent of slightly over 11.20 gallons of propane. If propane costs $2.50 per gallon, in this example, natural gas is the cheaper alternative. Environmental effects of propane vs. natural gas