Author may have been LaVyrle Spencer though I haven’t been able to find anything in her bibliography that matches.
It’s set in a motel in the 1930s (I think), along US Route 66, in Arizona or New Mexico. The female protagonist is the child of the aging owners, and comes home to help run the place. There are some bad characters inhabiting part of the motel, as well as the male main character. I don’t recall much more of it than that.