"El Valle: The Rio Grande Delta" by Seth Patterson & Lawrence V. Lof is a textbook focusing on nature in the Rio Grande Delta region. Published by the Gorgas Science Foundation, Inc, this hardcover book is written in English and covers the Rio Grande Delta area. The authors provide insights and information about the natural environment of the region, making it an informative and educational resource for students and nature enthusiasts alike. It is signed by Seth Patterson as well, who is also the main photographer of the book.