The park includes as many as 18 individual volcanoes, seven of which have been active since 1900, but it also protects 9,000 years of human history as well as important habitat for sockeye salmon and thousands of brown (grizzly) bears. After a series of boundary expansions, the present national park and preserve was established in 1980 under the Alaska National Interest Lands Conservation Act. It encompasses 4,093,077 acres, most of which (3,922,000 acres) is designated wilderness area. Unlike most ANILCA parks, the legislation for Katmai did not grant subsistence hunting in the national park portion, only within the preserve.
The 1912 eruption was the largest eruption by volume in the 20th century, erupting about 3.1 cubic miles of material. Novarupta generated as many as 14 major earthquakes with magnitudes of six and seven, a level of energy release virtually unprecedented during volcanic eruptions in modern memory, and over 100 earthquakes greater than magnitude five. Following the eruption, the summit of Mount Katmai collapsed about 3,900 square feet, forming the central caldera which has filled with water.
Below is the lake that has formed in the Kaguak Crater.
Initially designated because of its violent volcanic history, the monument and surrounding lands became appreciated for their abundance of sockeye salmon, the grizzly bears that fed upon them, and a wide variety of other Alaskan wildlife and marine life, including 29 mammal species, 137 bird species, 24 freshwater fish species, and four anadromous fish species (fish that migrate up rivers from the sea to spawn.) Specifically, Katmai NP has moose, gray wolves, beavers, porcupines, martens, and other mammals, including caribou which occasionally winter within the park. Marine mammals include hair seals, sea lions, and sea otters. Cetaceans include beluga whales, orcas, and gray whales.
The most important fish in the park are sockeye salmon, a mainstay for the diet of the bears, but also an important food source for bald eagles and others during the spawning runs in the park's rivers. Salmon enter the Naknek River drainage from Bristol Bay in June and July and spawn from August to October.
Katmai occupies the Pacific Ocean side of the Alaska Peninsula, south and west of Homer, south of Lake Clark National Park, and opposite Kodiak Island. The park's chief features are its 497 mile coast on Cook Inlet, the Aleutian Range with its chain of fifteen volcanic mountains across the coastal southeastern part of the park, and a series of large lakes in the flatter western part of the park.
The closest significant town is King Salmon west of the park where the park's headquarters is located, about five miles down the Naknek River from the park entrance. The Alaska Peninsula Highway runs from Naknek Lake near the entrance to King Salmon to the mouth of the river at Naknek but is not connected to the Alaska road system. Access to the park's interior is by boat on Naknek Lake. Another road runs from Brooks Camp to Three Forks which overlooks the Valley of Ten Thousand Smokes. The mountains of the Aleutian Range are about 15 miles inland and run from southwest to northeast.
The most significant volcanic event in historical times was the simultaneous eruption of Mount Katmai and Novarupta in June of 1912. Novarupta's eruption produced a pyroclastic flow that covered a nearby valley with ash as much as 300 feet thick. As the valley deposits cooled, they emitted steam from fissures and fumaroles, earning the name "Valley of Ten Thousand Smokes," a name coined by Robert Fiske Griggs who explored the volcanos' aftermath for the National Geographic Society in 1916: "The whole valley as far as the eye could reach was full of hundreds, no thousands—literally, tens of thousands—of smokes curling up from its fissured floor."
The steam vents have subsided, the valley has been eroded, and streams have cut canyons as deep as 100 feet, but often only five to ten feet wide.
The 1989 grounding of the oil tanker Exxon Valdez in Prince William Sound produced extensive contamination of the Katmai coastline. By early April, oil had reached Kenai Fjords National Park and then Cape Douglas in Katmai and points southwards in the following weeks, and 90% of the Katmai coastline had been polluted by the oil. The worst-hit areas were Cape Cjiniak and Chiniak Lagoon, Hallo Bay Beach and its lagoon, Cape Gull and Kaflia Bay, and Cape Douglas. Casualties in birds alone were estimated at 8,400 dead birds. Work resumed in 1990 to catch the last oil, with smaller efforts later in 1990s.
Weather at Katmai is variable, though reliably rainy or drizzly. Summer high temperatures average about 63 F. and winter lows range between −4 and 40. Fall is somewhat drier than the rest of the year and warm days can occur year round. Rainfall is heaviest near the coast with up to 60 inches, and lighter to the west.
Unlike most national parks in the United States, Katmai is almost exclusively accessed by plane or boat. You can not drive to Katmai, Brooks Camp, or King Salmon from Anchorage, Alaska. Most destinations in Katmai National Park Preserve are directly accessed via air taxi flights from Anchorage, Dillingham, Homer, King Salmon, Kodiak, and other nearby Alaska towns and villages.
The Pacific coast of Katmai offers a combination of amazing scenery, wilderness, and wildlife viewing opportunities. Most people who visit this area of the park go to watch bears, but there are many opportunities for sport fishing and wilderness trekking too.
Situated at the mouth of the Brooks River and the shore of Naknek Lake, Brooks Camp attracts people from all over the world to enjoy world-class fishing and learn about the long human history of the area. It is also a starting point for many backcountry adventures. Daily bus tours from Brooks Camp provide easy access to the geologic splendor of the Valley of Ten Thousand Smokes, site of the largest volcanic eruption of the 20th century.
From June 1 to September 18, the National Park Service operates a visitor center, ranger station, campground, and auditorium with daily ranger-led programs. The park concessioner, Katmailand, Inc. provides additional services and amenities including meals and lodging at Brooks Lodge.
The world's largest run of sockeye salmon occurs in Bristol Bay, Alaska, each summer. Part of that salmon run moves into Katmai National Park and Preserve through the Naknek and Alagnak rivers. In July and September, bears are everywhere at Brooks Camp. They can be found walking trails, fishing in the river, and even napping on the beach. During July, many bears can be seen fishing at Brooks Falls which is about 1.2 miles from the Brooks Camp Visitor Center. In September, most bears are seen at the mouth of the Brooks River.
There are three viewing platforms located in Brooks Camp along the south side of Brooks River. The Falls Platform is located immediately adjacent to Brooks Falls, the Riffles Platform is located about 100 yards downstream of Brooks Falls, and the Lower River Platform is at the mouth of the Brooks River near Brooks Lodge.
The Falls Platform has a limited capacity of 40 people. When the Falls Platform is at maximum capacity, rangers maintain a waiting list and everyone is limited to one hour at a time on the platform.
This system helps to provide equal access to the Falls Platform during peak days of visitation. If you visit Brooks Camp in July, expect crowded conditions at Brooks Falls when sights as seen below are common.