ANTELOPE ISLAND, Utah (AP) — Utah state wildlife officials have gathered mule deer on Antelope Island and flown them by helicopter to assess the health of the herd.

The Standard-Examiner reports that about 50 blindfolded and restrained deer were flown this week, typically two or three at a time dangling below the aircraft in orange bags.

They were taken to the island’s Fielding Garr Ranch, where biologists and other Utah Division of Wildlife Resources staffers checked various aspects of each animal’s health, including hind feet, body length and body fat.

Authorities say the goal is to make sure the herd is at a healthy size, given the resources available. There are 400 to 500 deer living on the state park located on the Great Salt Lake.