If I were to guess, I'd say the games are based on abandoned mining towns in either New Mexico, or Arizona. I couldn't find one named Echo, but there are a lot of similarities, like the Mesita tribe's whereabouts, and the temperature and landscape. What's interesting, is that there is a city called Pueblo in South Colorado, which is the name of the college that Jenna and Chase were enrolled in during the game. TJ Chase and Jenna's long drive at the beginning of the game would be very similar to driving to Western New Mexico or to eastern Arizona.
I can't find a single place named Echo around those parts.