Julius Gorton pushes a rectangle-shaped rock into the ground then shakes it. Still loose. He takes the pick axe next to him and hammers it down.
“OK, maybe it just needs to dig out a little bit,” Ella Marshall says. She moves the rock aside and starts digging a gap into the dirt, her hands protected by purple gardening gloves. They wedge the rock back in and hammer it down a few times. Satisfied, they start adding more rocks around it.
They play tetris with the rocks gathered from the mountain, filling gaps and turning each one to see how it fits best. Gorton puts a rock down; Marshall hammers it into place. They’re building a rock rundown, a type of erosion control structure, along a natural drainage on Mount Lemmon…