Coalinga, LIpantitlan

[ANTHONY APPLEYARD]

I have come across a guesstymology or urban myth that the name of the
place Coalinga http://en.wikipedia.org/w/index.php?title=Coalinga in
California came from "Coaling [station] A" where steam railway engines
got coal. Is this correct? Or does the name refer to a different sort
of thing that hisses, namely Nahuatl [coatl]?

Lipantitlan http://www.tpwd.state.tx.us/park/lipan/lipan.htm in Texas
looks Nahuatl, but the initial L looks unnatural for Nahuatl. Is this
[lipan] the name of a local native tribe?