Non, Sport climbing, Top rope
Alpine climbing NCCS rating
Grade I
Elevation Gain
550.00 ft (167.64 m)
4.00 mi (6.44 km)
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In the Chugach National Forest, a mountainous area between the ocean bodies of the Turnagain Arm and the Prince William Sounds, is an area known as Portage Pass. Within lies but one of many of south-central Alaska’s easily accessible glaciers: Byron Glacier.

A stone’s throw and one 4-mile, one-way tunnel away from the perpetually precipitous town of Whittier (and as locals say, “It’s always sh*ttier in Whittier”), the Byron Glacier valley is subject to notoriously bad weather. It rains as many days as not through the summer climbing season, but on those blue-bird sunny days it’s absolutely stunning.

In the right season, however, generally June onward, you can detour much farther up the valley, not too far past The Outer Limits boulders, to view the popular ice caves at the toe of the glacier. Farther up the far slope, you can see the proud and prominent head wall itself. Byron is one of Alaska's most visibly shrinking glaciers, retreating almost halfway up the mountain in the last decade alone.

To access from the spacious parking trailhead (which includes several RV spaces for larger vehicles), hike for 1.25 miles along a nearly flat, well maintained gravel trail. Due to ease of access, this is one of the most popular hikes in south-central Alaska for tourists and locals. You will see all kinds on the hike in until the gravel ends. The trail finally ends at an intermittent talus and snowfield, which is actually just avalanche debris pile once the surrounding peaks “let go” throughout the spring.

The snowfield more or less stays around all summer, though it shrinks steadily as the season progresses. Snowshoes or skis are unnecessary, though sometimes you may be wishing you had them as you’re slip-sliding around the soft, melting surface on a sunny day. Be mindful of the edges where the snowfield meets the boulders, as there is often a hidden cornice underneath that could result in a nasty, ankle-breaking post hole.

The rocky portions around the boulders themselves require classic Alaska talus hopping that makes for a tiring and well-earned approach. These rock fields also make for poor boulder landings. While many of the landings have been built and cleaned as much as possible, large, unmovable boulders still make them sketchy at best. Bring friends and lots of pads.

The rock here is a mixture of slate and greywacke, a refreshing difference from the chossy Chugach conglomerate surrounding the valley. It is far harder and more metamorphosed due to glacial pressure. If you’ve never climbed on glacial firmed rocks, you’re in for a treat.

With lots of "holds" you don’t want to use and every other hold facing the wrong way, Byron demands you get creative with your beta. No climb (even the easy ones) are a gimme. Since Alaska has a relatively small climbing scene, you will find no overly chalked holds, and you will have to find the hidden holds for yourself once (probably after you gotten past it and looked back to say, “Oh, there's the good hold!”). Look out for the occasional mud vein that seeps and makes an enticingly juicy hold perpetually wet.

The Boulders

There 147 problems, ranging from V0 to V11 in the last guidebook (Alaska Bouldering, by Todd Helgeson, David Funatake, and Kelsey Gray), but lots of development has happened since then, and many of the standing projects have been sent. Check with locals for the full experience, but unlike other areas in Alaska it’s easy enough to climb in Byron with just a guidebook.

There are four main areas:

  • The Jungle (2 boulders, 15 problems; 60.76852 N, 148.84474 W): Named so for a reason, The Jungle lies behind a brutal swath of alders. Try:
    • Chasing Bliss (V9): A “minimalist” boulder problem if ever there were one. Fight your way up almost non-existent holds.
  • The Arkenstone (4 boulders, 24 problems; 60.76403 N, 148.84855 W): These problems are easier to climb in early seasons (like early May) when the landing is made much better by snow. Try:
    • Crooked Hook (V11): a formerly the 6-year standing Arkenstone project, a brutal one-move wonder climb finally went down early in summer of 2019.
  • The Goods (7 boulders, 61 problems; 60.76120 N, 148.85031 W): The first of these boulders (and the most proud) is the Erotics boulder, a huge prow right at the top of the main talus field. The rest of these boulders are located on the other side of the main talus field, right where it tapers off on the creek bank before next talus field leading to the ice caves and Outer Limits. Try:
    • Breakfast of Champions (V3): Great warm up for your mental game on heady topouts notorious in the Byron boulders.
    • Glacial Erotics (V4): The first climbed in the valley and oh-so appropriately named. With a view of Byron glacier right in the background, this burly problem with a tricky topout (especially if you’re short) high off the deck of a bad landing is absolutely must-do. Make it into a V7 by doing a sit start on the arête.
    • Shadow of Time (V4): The start holds sure aren’t inviting, but if you can pull on them, the climb feels fabulous. Just don’t blow the somewhat precarious topout looming over some rusty boulder below. Or if you do, make sure you’re up to date on your tetanus shots.
  • Outer Limits (3 boulders, 46 problems; 60.75748 N, 148.85533 W): Really, there are more boulders than three, but they’re clustered together in tight pods, so they’re classified in three main groupings. While the hardest to get to, this area has the highest concentration of climbs in a wide variety of grades. This area is the last to melt out for the season, and typically is not climbable until late May. Try:
    • The Allspark (V2): Classic Alaska climbing with a weird and sketchy topout over a not-great landing.
    • Dark of the Moon (V8): Probably goes closer to V10 but a beautiful line with stellar movement.
    • Hurts So Good (V7): Super soft. Opposite to Dark of the Moon, this V7 feels more like V5, but don’t let that deter you. It’s a super fun climb and a worthy tick.
    • Glacial Alchemy (V5): An absolutely horrifying 20 feet of blank slab that sees a whole lot of sun. A stunning line for the brave of heart. Try if you dare, but have lots of pads.

The Rope Routes

Byron Glacier has only 24 routes, ranging from 5.8 to 5.14, but they are much higher quality than the nearby routes along the Seward Highway. As these routes lie on the east valley walls, they receive blistering afternoon and evening sun that makes already slick rock even greasier.

The rope routes lie across the creek from the boulders. To access the walls, you can either fjord the river or hook left across the snowfield. This can be scary depending on snowfall, especially on the pack that crosses the creek itself, which can be hollow beneath you from running water. You can’t miss the bolts. Note that these routes are often wet, as the snowpack above seeps all summer long. Try:

  • Crisco Kid (5.10d): The name says it all, but it’s an all-time classic route for not just area, but the state. With a somewhat uncomfortable belay and a high first bolt onto slippery, somewhat slabby goodness, you’ll never feel prouder of a clean send.


Be aware that Byron Valley is an avalanche bowl surrounded by high peaks that see annual snowfall over 200 inches. It is notoriously one of the most dangerous avalanche zones in the area. IT IS NOT RECOMMENDED to visit the Byron valley during the spring breakup. March and April are absolutely too dangerous to visit this location; if an avalanche comes down, there is nowhere to escape. By May, most of the climbing is safely accessible, though the Outer Limits may still be under snow.

Logistics + Planning

Preferable season(s)




Parking Pass


Open Year-round


Open from

March 01 to September 30


Stunning views. Up-close glacier experience. Rock variety. Interesting hike. Low incline.


Seasonal avalanche danger. Difficult terrain. No path for part. Popular trail.

Pets allowed


Trailhead Elevation

164.00 ft (49.99 m)

Highest point

514.00 ft (156.67 m)


Geologically significant
Potable water



Typically multi-day


Permit required


Primary aspect

West facing

Drinking water

Unfrozen water



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