KODIAK, Alaska (AP) _ A mistake by an elk herd's frightened leader may have sent 40 animals tumbling to their death over a cliff on Afognak Island, biologists say.

''It was gruesome,'' said Larry VanDaele, one of two state game biologists assigned to examine the tangled mass of dead elk at the bottom of a cliff.

VanDaele and Roger Smith flew last week from Kodiak to the island in the Gulf of Alaska, where a group of hunters traveling by skiff first spotted the dead animals Oct. 24.

Smith said it appeared the animals were on a trail near the top of the cliff when the leader made a mistake.

''Elk travel in single file and there were many well-used trails along the edge,'' he said. ''At one point, they went over and fell 200 to 300 feet, then slid down an avalanche chute to the beach. I'm sure they all died instantly,'' he said.

Game biologists in the Alaska Department of Fish and Game said the fall was extremely unusual.

''Obviously something frightened the elk,'' Smith said. ''Either hunters or possibly an aircraft crowded them out on the point. We have no witnesses, so all our evidence is circumstantial.''

The department closed the area to hunting soon after learning of the mass kill.