You know, all the mesas you see as you drive from TX to AZ mark where the coast used to be when the planet was much warmer. Right at the TX/NM border, you can make it out clearly, where the coastline was, the offshore islands, all of it. The vast majority of Texas was under shallow water, just like the gulf is today off the coast of Texas. You might want to buy a further East if you want waterfront, around Tucumcari would work.