This national monument features stunning geological formations in the Sonoran Desert. Its rugged beauty also means you must ...

Alex Mintzer has been counting ant colonies at Organ Pipe Cactus National Monument for more than 30 years. It’s a feverish midsummer night in southwestern Arizona, and the air feels electric because ...

And though there are older, larger cactus forests in the Southwestern U.S. — Organ Pipe Cactus National Monument and Saguaro ... as a crossing for illegal migrant activity, so situational ...