Given the following context:  The film opens with military veteran helicopter pilot and guide Don Stober flying individuals above the trees of a vast national park. He states that the woods are untouched and remain much as they did during the time when Native Americans lived there. Two female hikers are breaking camp when they are suddenly attacked and killed by an unseen animal. The national park's chief ranger, Michael Kelly, and photographer Allison Corwin, daughter of the park's restaurant owner, decide to follow a ranger to the primitive campsite to check on the female hikers. There, they discover the mangled corpses of the two girls, one of which has been partially buried. At the hospital, a doctor tells Kelly that the girls were killed by a bear. The park supervisor, Charley Kittridge, blames Kelly for the attacks, saying that the bears were supposed to have been moved from the park by Kelly and naturalist Arthur Scott before the tourist season began. Kelly and Kittridge argue over closing the park, before deciding to move all hikers off the park's mountain while allowing campers to remain in the lowlands. Kelly calls Scott, who tells him that all of the bears are accounted for and this specific bear must be unknown to the forest. During a search of the mountain, a female ranger stops for a break at a waterfall. Deciding to soak her feet, she is unaware that the bear is lurking under the falls, and she is attacked and killed. Kelly recruits the helicopter pilot, Stober, to assist in the search. Flying above the forest, they see what they believe to be an animal, only to discover the naturalist Scott adorned in an animal skin while tracking the bear. He informs them that the animal they are looking for is a prehistoric grizzly bear (a fictional Pleistocene-era Arctodus ursos horribilis) standing at least 15 feet tall and weighing 2,000 pounds. Kelly and Stober scoff at the notion.  answer the following question:  What is the last name of the person that helps the park ranger find the naturalist in an animal skin?
Stober