It was set in Alaska I think, or perhaps north-west Canada. It involved several hunters who stumbled into a “lost” valley where they discovered preserved specimens of all sorts of animals, ranging from current species right back to prehistoric animals. Apparently an alien life force had landed a probe in the valley thousands of years earlier. The probe had been programmed to collect and preserve a specimen of each species. It had been operating efficiently ever since. The rest of the story details the hunters’ attempts to outwit/outrun the probe and avoid becoming preserved specimens themselves.
It’s a long time since I read the story. Nearly 30 years.
Any thoughts?