The Yuma myotis is common and widespread in California. It is uncommon in the Mojave and Colorado Desert regions, except for the mountain ranges bordering the Colorado River Valley.
Optimal habitats are open forests and woodlands with sources of water over which to feed.
Feeds on a wide variety of small flying insects found by echolocation. This species usually feeds over water sources such as ponds, streams, and stock tanks. The species also has been seen roosting in abandoned swallow nests and under bridges. Separate, often more open, night roosts may be used. Maternity colonies of several thousand females and young may be found in buildings, caves, mines, and under bridges.