A Reynolds Nationwide semi tractor and trailer out of San Antonio, Texas, caught fire on Melon Hill outside of Rangely Saturday afternoon when hay stacked too close to the semi’s exhaust pipe ignited, spreading to other bales and falling onto the tractor as the driver separated it from the trailer.RANGELY I A semi-tractor trailer hauling approximately 20 one-ton bales of hay caught fire Saturday afternoon, destroying the tractor and closing Highway 64 west of…