Coming from an Alamosa born native, 35 year railroader whose career started in Alamosa and an Adams State College educated local idiot, I would say the San Luis Valley is pronounced by the locals "San Lewis" (yes, including the local guys who are Spanish) Cumbres is pronounced by the locals as comebers Pass. I hate it when I hear Coombres (rolling the R) although I hear Coooombres more from rail buffs than I do the locals. I know the proper Spanish pronounciation, I took the subject in school for years but this is the way the locals speak the lingo FYI.
Woody Woodward
( I would love to watch a video where the moderator got it right just once as per local talk and the way the railroad guys say it)