A population of lizards unique to Phoenix's South Mountain Park is making a move so the Valley's newest freeway can be built.

The South Mountain Freeway stretch of State Route 202 (commonly known as Loop 202) will cut through the far southwest corner of the park. While construction there isn't scheduled to start until mid-2018, teams of biologists worked this summer to find and relocate chuckwallas living in the area, the Arizona Department of Transportation says.

Chuckwallas are common in the American Southwest and northern Mexico, and if you've hiked up Camelback Mountain or on other trails around Phoenix, you've likely seen a chuckwalla doing push-ups on a sunny rock. But male chuckwallas at South Mountain Park have bright orange tails — they're the only chuckwalla population known to have that coloration. And rather than flee when threatened, chuckwallas often wedge themselves deep in rock crevices, meaning the freeway construction could end up harming them.

The biologist teams used flashlights and sometimes pry bars to get to the chuckwallas, then captured them and released them several hundred feet away, ADOT says. About 120 of the lizards were relocated, but not before they were weighed, measured and tagged with transponders so biologists can identify them during future surveys.

"With the work that we are doing in collaboration with our partners, we believe the chuckwalla population will continue to thrive in the area surrounding the South Mountain Freeway," ADOT biologist Kris Gade says.

Other animals that could be impacted by the freeway include desert tortoises and burrowing owls. ADOT says it's working to address those impacts.

The freeway is expected to open by the end of 2019.