The topic of the border wall between the United States and Mexico continues to be broadly and hotly debated: on national news media, by local and state governments, and even over the dinner table. By now, broad segments of the population have heard widely varying opinions about the wall's effect on illegal immigration, international politics, and the drug war. But what about the wall's effect on animals? Krista Schlyer vividly shows us that this largely isolated natural area, stretching from the Pacific Ocean to the Gulf of Mexico, is also host to a number of rare ecosystems.