The tiny town of Marathon is considered the easternmost gateway city to Big Bend National Park, so Marathon has several lodging options including Eve's Garden Organic Bed and Breakfast and Ecology Resource Center. From their website:
"Eve’s Garden is a research level organic gardening demonstration site and an urban hacienda, combining to provide a comfortable Bed and Breakfast environment and a conversational forum to address issues regarding the ecology we live in.
Every effort has been made to combine elements of “art”, “architecture”, and “ecology” in the layout and construction of this unusually progressive piece of work. A large amount of recycled content, strawbale buildings, paper adobe/fiber cement buildings, high Mexican contemporary color treatments, and a focus on locally produced food, conspire to create an aura of thoughtfulness."