Here is one more bat, the third species that roosted in the sandstone cave.
It is distinctly darker than the long-eared species of Myotis, and I suspect it is either the Yuma myotis (Myotis yumanensis) or the California myotis (Myotis californicus).
You can tell them apart by the size of the feet. The California myotis has little feet.
Getting bat pictures is gratifying, but you need high quality photos to identify bats to species, and even that is not always enough.
Sometimes you have to look at their teeth.
Now to see some truly excellent bat photos that show diagnostic characters, have a look at Michael Durham's webpage here.