Geology

Formation

Formed by plate tectonics as the Pacific Plate subducted under the North American Plate, the Chugach Mountain Range was built as mountains on the ocean floor were sheared off and piled onto the North American Plate. The abrupt coastal range blocks moist ocean weather systems from making it inland, causing them to release most of their moisture on the mountains. Much of the precipitation falls as snow due to the northern latitude and the high elevations. Each year, an average of 80 feet of snow falls on the highest peaks of the central Chugach Range. More snow falls in this area than can melt, leading to the formation of glaciers.

Within the Central Chugach Range, there are ice fields and hundreds of glaciers. During past ice ages, the Knik Glacier joined with others in the area to form a massive truck glacier that carved a deep trough about 30 miles long through the Chugach Range before joining other massive glaciers nearby and forming the Knik Arm of Cook Inlet. As the massive glacier retreated during warmer periods, the ocean inlet would have followed it back through the valley resembling a Fjord.

Since the last ice age, the glaciers have receded and separated into individual glaciers. As the giant rivers of ice flow down the mountains, they pluck giant rocks from the mountains, grinding them down into smaller and smaller pieces. Water draining from under the glacier carries this mix of sediment out and deposits it on the valley floor, flattening it out and lifting the floor little by little over time. A combination of glacial meltwater, melting snowpack, rain, and strong winds continue to distribute the sediment across the valley and away from the glacier out towards the sea.

The large gash cut into the mountain range by these glaciers formed the Knik Valley. Here you’ll find the shortest distance across the mountain range from inland Alaska to the coast at only 30 miles compared to an average width of 60 miles across the remainder of the range. Being surrounded by tall mountains on three sides combined with a short distance to Prince William Sound and the presence is hundreds of square miles of ice allows for a unique and distinct microclimate within the Knik Valley.

Knik Glacier

The Knik Glacier is a massive flowing river of ice with an area of about 145 square miles. It’s the crown jewel of the area. Geologists have estimated the glacier’s age to be about 600,000 years old. Although there are many other glaciers within sight, this is the largest and most visible.

Moraines near Knik Glacier in Alaska
Moraines near Knik Glacier in Alaska

Over the 30 miles of its length, the glacier descends nearly two miles in elevation as it works its way down the mountains to the valley floor. The ice can be thousands of feet deep and the walls of the toe can rise as much as 400 feet above the lake at its base. During the summer, large blocks of ice break off the glacier and fall into the lake creating icebergs.

Winds blow the icebergs across the lake where they pile up in front of the moraine. Iceberg hopping is popular with guests. If conditions are right, you can get out a half-mile onto the iceberg field. Sometimes guests will even go swimming in the 32-degree water!

Dangers

The more incredible the place, it seems, the more dangerous it is.The Knik Valley is no exception.There’s a reason we guide tours and don’t rent machines!

This is a wild place where things can and do go wrong and the consequences are real.It’s not a typical tame and maintained tourist destination.We’re deep in the backcountry without cell service on our own.This is where you come when you want to experience the real Alaska as real Alaskans do.It’s how you get an adventure to top all others.

Regardless of the dangers, your guide will keep you safe and out of harm’s way.Each guide is well-versed in the various risks and can avoid them or respond to them accordingly.By following your guide’s instructions throughout the tour, you will have a safe and successful trip that will also be exhilarating and unforgettable.

[Here’s a quick list of dangers you might encounter on your adventure:

Water – The valley is filled with rivers, creeks, ponds, and lakes.Generally, even in the dead of summer, the rivers and lakes are cold enough to give you hypothermia in minutes.There’s also rivers and creeks that can wash you and your machine away during certain times of year.

Kettle Lakes near Knik Alaska

Mud and Quicksand – These can get you stuck in a hurry.With quicksand, you won’t even know it’s there before it’s too late.It’s easy to break a machine trying to get unstuck.

Landslides, Falling Rocks and Avalanches – Some areas are prone to landslides and avalanches.Cliffs and canyons experience falling rocks.

Ice – Whether your crossing a frozen river, walking on icebergs in the summer, or exploring the toe of the glacier in the winter, ice can be very dangerous.Proper slip-resistant footwear should be worn when traversing ice.Chunks of glaciers break off suddenly and icebergs regularly roll over in the water.This is where you should be most careful.

Wildlife – There’s a lot of big creatures in Alaska and encounters can happen at any time.Bear encounters happen and can be dangerous, but most people don’t know that many more people are killed by moose each year.Cow moose with young children can be very protective and hypersensitive and bull moose can be aggressive during the rutting season.Even beavers can be vicious.So remember to take precaution during any encounter with wildlife.

Confusing Trail Network – The network of trails we use are not marked and are very confusing since many are seasonal and often change by the day due to conditions. We’ve never lost anyone on a tour, but we’ve been on searches for other people who got lost back there.Just one more reason to stick with the group.

Explore the wetlands near Knik Glacier in Alaska

Getting Stuck – Depending on conditions, it’s common for someone to get stuck at some point on the tour.If you were alone in a rental, it could be a life or death issue.On a tour, it’s just part of the adventure!Your guide will be able to get you out no problem or he might just give you the instruction you need to get out yourself if you prefer a challenge.]