grand canyon

Claudine LoMonaco

Larry Stevens is an evolutionary biologist. For the last 41 years, he’s dedicated much of his life to the study and salvation of springs, little spots where water bubbles out of the earth.

Stevens stands in huge alcove carved out of a sandstone cliff on a remoter trail in Grand Canyon National Park. He holds a measuring cup under a stream of water that drips from a cluster of bright green ferns.

“Dripping Springs is a fairly small spring,” Stevens says. “We’re looking at half a gallon a minute of flow.”


Each year an average of 250 people are rescued from inside Grand Canyon. Many of them are hikers unprepared for the substantial temperature difference between the top of the rim and inside the canyon. Hikers can be surprised as they start with pleasant 70-degree temperatures at the top and approach a dangerous 100 degrees, or more, near the river.

Now the National Weather Service is working to address that gap in perceptions. With help from the Park Service, it installed two weather stations inside the Canyon: one at Indian Garden Campground, the other at Phantom Ranch.