Smaller mammals include coyotes, marten, red fox, wolverine, river otter, beaver and lynx. Marine mammals include sea lion, beluga whale, harbor seal, and porpoise. Both black and brown bear species are present in the park. Black bears use all areas of the park and preserve, except the higher elevations. Brown bears are most numerous along the coast. A recent survey found that about 219 bears graze in salt marshes during the summer in the coastal areas of the park. Caribou have recently declined in population size from 200,000 to 30,000 due to an unknown cause. Weather in the park is extremely variable. Marine air from the Pacific Ocean meets drier air of the continental airmass over the park. The average summer temperature is between with highs around and typical winter lows of . Snow can happen at any time. The earliest human presence known in the area of Lake Clark was at Bristol Bay. People of the Paleo-Arctic Tradition lived there between 10,000 years before the present and 7500 BP. These people were followed by the northern Archaic tradition between 6,000 BP and 4,000 BP. Two sites from this tradition have been documented in the park. The Arctic small tool tradition followed from about 5,000 BP to 3,000 BP. The Norton tradition came between 2,200 BP and 1,000 BP, concentrated around Bristol Bay. The Thule Tradition was established around 2,000 BP and lasted until historic times. The northern Athabaskan Dena'ina presently live in the area. Kijik village is the primary archaeological site in the park, inhabited by Dena'ina until the early 20th century. Settlements have also been documented around Chinitna Bay. The Cook Inlet was surveyed by British Captain James Cook in 1778. In succeeding decades Russian traders established themselves in the region. The major settlement during the 19th century was at Kijik, with a population in the low hundreds. By the 1890s American traders had arrived in the area, meeting a native population that had been greatly reduced by imported diseases. Kijik has been designated a National Historic Landmark district. In 1930 the first floatplane landed on Lake Clark. In 1942 the first air taxi service was provided to Lake Clark, run by Leon "Babe" Alsworth, Sr. to Port Alsworth. Apart from Port Alsworth, there are five other communities near but not within the park: Lime Village, Nondalton, Iliamna, Newhalen and Pedro Bay.