Salmon research can be dangerous when you’re near an active wolf den. Last week, a female seasonal researcher with the U.S. Forest Service narrowly missed being killed by wolves in the Okanogan-Wenatchee National Forest in Washington. The woman, who said she did hear yips and barks prior to the attack, had to climb 30’ into a tree after “efforts to scare off two adult gray wolves by yelling and using bear spray were unsuccessful,” the Methow Valley News reports. Fortunately, a Washington Department of Natural Resources (WDNR) helicopter was stationed nearby and officers were able to rescue the woman. She was found in a tree with the two wolves circling her.

According to the Washington Department of Fish and Wildlife (WDFW), the researcher was close to a wolf denning site or rendezvous area—an area where pups live temporarily until they are old enough to join the pack as adults—and the wolves were members of the Loup Loup pack. The U.S. Fish & Wildlife Service (FWS) confirmed that, according to GPS data, the researcher was near a den site.

Joe Stohr, acting director of WDFW, told the Methow Valley News that “it’s common for wolves to bark, howl and approach people or other animals when protecting their pups.”

The incident occurred around the Tiffany Springs campground and officers with the WDNR were told they could kill the wolves if the animals were still “surrounding the female,” the Methow Valley News reports. However, once the helicopter arrived, both wolves fled the scene.

The woman, who remains unidentified, was unharmed during the incident.