Complex sentence: The Carson route across the Lahontan Valley is loosely approximated by modern U.S. Route 95 & U.S. Route 50 and proceed south from modern Lovelock towards an area west of modern Fallon called Ragtown, which had the last usable water on the Carson River.
Split into simpler sentences: The Carson route across the Lahontan Valley is loosely approximated by modern U.S. Route 95 & U.S. Route 50. It proceeds south from modern Lovelock towards an area west of modern Fallon called Ragtown, which had the last usable water on the Carson River.