Aniakchak, Alaska, US
|Usual Difficulty||I-IV (for normal flows)|
|Avg. Gradient||30 fpm|
|Max Gradient||83 fpm|
The Aniakchak River, a Federally-designated Wild and Scenic River, is located within the Aniakchak National Mounment and Preserve providing an opportunity for a remote river expedition on the Alaska Peninusla. Trips usually take place during the month of July. Plan for 3-4 days but be prepared for longer as weather conditions often dictate the schedule.
The Aniakchak Volcano underwent a catostrophic explosive erruption approximately 3400 years ago that formed the current caldera. Smaller erruptions have occurred more recently, with the last one in 1931. Surprise Lake, located within the 5.9 mile diameter caldera, is the source of the Aniakchak River. This caldera has its own microclimate marked by consistently wet weather and harsh winds. Despite this it offers opportunities for exploration and hiking across the volcanic landscape.
From the lake the river begins at a slow pace for the first mile before entering the "Gates", a 1500 foot gash in the caldera wall. Here the river drops at a rate of 73 feet per mile with class IV whitewater. The river remains class II/III for the next 10 miles (if you're in an inflatible be sure to pack the patch kit as the sharp volcanic rocks can do a number on your boat). At the confluence of Hidden Creek the river enters the steep 83 feet per mile section where volcanic bedrock on either side and boulders in the channel constrict the flow. The pace of the river begins to slow considerably over the next five miles as you leave this section and continue the remainder of the journey on a low-gradient alluvial river that takes you to the ocean.
The river system supports all five species of salmon and Surprise Lake provides spawning habitat and a nursery for sockeye salmon and artic char. Dolly Varden are also present. Wildlife are abundant and brown bear are common along this river so be sure to take proper precautions and be prepared for encounters.
LOGISTICS: The expense of getting to this river and the unpredictable weather keep usage low. You can get commerical service into King Salmon or to Port Heiden. From either of these airstrips you'll need to arrange for a float plane charter to Surprise Lake. King Salmon is further away (150 miles vs. 20 miles) but offers more options. You will also need to arrange for pick up at the end of your trip where the river meets the ocean at Aniakchak Bay. Float planes can land in the bay or wheel planes can land on the beachhead. Poor weather conditions can delay flights so plan accordingly. There is a shelter at the beach for boaters awaiting pick up. This region is extremely remote with no practical access to outside assistance.