Isabelle Glacier

According to the United States Geological Survey, a glacier is “a large, perennial accumulation of crystalline ice, snow, rock, sediment, and often liquid water that originates on land and moves downslope under the influence of its own weight and gravity.” I’m guessing, then, that when a glacier shrinks enough, it won’t be massive enough for its weight to overcome friction and it will stop moving and it will no longer be a glacier, but a permanent snowfield.

There are fourteen named glaciers in Colorado. I’d be surprised if all these fourteen are still glaciers by the end of my lifetime.

Isabelle Glacier forms the headwaters of South St. Vrain Creek and clings to the Continental Divide between Apache Peak and Shoshoni Peak in the Indian Peaks Wilderness. The easiest access is from the Brainard Lake Recreation Area.

Tuesday, July 12

Not long ago, Brainard implemented a timed-entry pass system much like that in use at RMNP. Passes are made available two weeks before the date and when I went to pick a date and make my reservation, there were plenty of passes still available for each day in the fourteen-day window. I picked up a pass in the earliest time slot, 5 am to 8 am. I bought a pass for parking at the Brainard Lake picnic area. There are permits available for the small lot right at the Long Lake trailhead, but the early times sell out pretty quickly.

The ProTrails writeup for the hike to Isabelle Glacier says it’s an 8.75-mile round-trip with a net elevation gain of 1,510′. That’s from the Long Lake trailhead, which is about a mile (and 200′ of elevation) from where I parked. I neglected to account for this when I was thinking about how long the hike would take. It turns out, I also didn’t give much credit to the overall steepness of the trip.

I arrived at the parking lot a few minutes before 8 and was quickly on my way. Because I took a somewhat more scenic route from my car to the Long Lake trailhead, it took me half an hour to get there. The trail from the trailhead to the first sight of Lake Isabelle is fairly typical for the area: well-maintained, wide, and busy, through forest. Long Lake is, well, pretty long: about six-tenths of a mile. The valley the trail traverses is wide and for the most part, the trail doesn’t rise much above the floor. The South St. Vrain meanders a bit and forms the usual pools and marshes in the grassy meadows. There aren’t many views through this forested section of trail, although there are the occasional glimpses of Niwot Ridge and the cascades formed just below the outlet of Lake Isabelle.

At Lake Isabelle, there’s a trail junction. Continue straight to see the lake or proceed up to Isabelle Glacier. Take a right turn to head up to Pawnee Pass. One could go that way to summit Pawnee Peak or Shoshoni Peak or to visit Pawnee Lake, but I’m not sure I’m up to any of those. Either peak is about a thousand feet higher than Isabelle Glacier and add a bit of distance. Pawnee Lake is something like 1,600′ below the pass, so you’d be looking at dealing with more than 3,000′ of climbing.

Lake Isabelle is another significant body of water, measuring about half a mile from east to west and spanning the entire width of the canyon. The trail skirts the north shore of the lake, sometimes right at the water level, sometimes navigating through talus fields. For the entire length of the trail, from the Long Lake trailhead to the glacier, the trail is intuitive and easy to follow, except for two or three short stretches of talus.

Just west of the lake, the trail climbs a bit to a rocky outcropping where the stream makes a wide and scenic cascade. Those hikers not up to the challenge of reaching the glacier would find this area a very pleasant place to stop and take in the scenery.

As is typical for hikes through valleys with multiple lakes, the trail is alternately fairly flat and somewhat steep. Each lake sits on a bench, with a short ascent from one bench to another. The bench above Lake Isabelle lacks a lake and instead is filled with a sea of willow. The trail crosses the stream in the midst of the willow. In mid-July, the flow of water is still near its peak, and in addition to the main stream, there are several smaller rivulets to cross. None of these crossings are treacherous, but some are challenging.

After navigating the willow, the trail climbs to the next bench. I met a hiker headed down and asked him if he’d been to the Glacier. He hadn’t. He was stymied by a field of snow. I’d spotted this from below and noted the tracks that ran across it. For today’s hike, I consulted the weather forecast for the area which said we’d see a high temperature of about 70 degrees. I decided to bring a hoodie rather than microspikes. At this point, I was wondering if I made the best choice: even at 10:30, it was about 70 degrees and sunny. And this snow field looked to be fairly steep.

An aside here: For most of my hiking history, I eschewed trek poles. I always figured that on any given hike I might find poles of limited usefulness and therefore not worth the weight penalty. Recently, I’ve been reassessing. I’ve decided that, if I’m going off-trail, I should bring the poles. This hike had no off-trail component, but I figured that poles might be handy on the final steep section. From the trailhead to Lake Isabelle, I carried them on my pack. I relied on them quite a bit for all my water crossings. (Carrying them on my pack makes me wider – they stick out on either end. I’m still getting used to that. I have to account for this in narrow spots.)

The snowfield looked to be about a hundred yards across, with boot prints that went neither uphill nor downhill. When I stepped onto the snow, I decided that spikes wouldn’t have helped much. The snow gets pretty soft when it’s been in the sunshine all morning and I don’t think spikes would have improved traction. But I was quite happy to have my poles with me. This crossing was near the top of this snowfield and a slip might have meant a slide of a couple of hundred feet. But it wasn’t as steep as it looked from below, so I continued.

There’s an unnamed tarn on this bench, only a few yards past the snowfield. Here I met another hiker. He asked if I’d seen anybody else headed this way and told me that he was the only one up here. He said I had about a third of a mile to go, but that it was “straight uphill”. He was quite impressed by the glacier, calling it a “bucket list” item.

Standing on the talus shore of the tarn, it’s a bit intimidating to look at the slope the trail ascends. The trail has many switchbacks and quite a bit of effort went into constructing it. But from below, there’s no sign of a way up.

Usually, when on a treeless slope, it’s pretty easy to see where the trail goes. Here it’s almost as if you’re on a stretch of magical trail. The trail seems to exist for only a short distance ahead and behind. The trail coalesces in front of you from nothing and decays back to nothing behind you.

One of the trail’s switchbacks is next to a falls. There’s not a huge volume of water, but it falls thirty or forty feet straight down and is fairly wide. It doesn’t exactly roar but makes a fair noise. Just as the trail seems to annihilate itself once it’s behind you, the sound of the falls quickly fades to nothing just a few steps up the trail.

After a final stream crossing, the trail dumps you onto a rim of rocks surrounding another tarn, this one full of snow and ice and water. The glacier stretches above and to the west. By surface area, it’s a bit smaller than Lake Isabelle. Not very long ago, some intrepid skier hiked to the top for a single run down the glacier. How badly must you want to ski, to carry your skis as far as I just hiked, then climb another 500-600′ of very steep snow?

There are two or three other tracks in the snow. They’re not made by man or beast, but the tracks of rocks that have fallen from above. When I used to hike to Emerald Lake every Memorial Day, I’d often hear the crack and rumble of falling rocks. Sitting here at the glacier eating my lunch I heard that noise again. I couldn’t help but think of the recent major rockfall in Chaos Canyon, even though I knew it was just a single, small rock.

The scenery is very dramatic. Isabelle Glacier is draped off the ridge between Apache and Shoshoni peaks. Navajo Peak is almost due south and has a smaller, unnamed glacier clinging to its steep slope. Niwot Ridge runs off Navaho Peak nearly due east for a mile and a half or more. My lunch spot was at almost exactly 12,000′ elevation and all the steep, craggy peaks surrounding it rise another thousand feet or so.

When planning the hike, I figured it would only take two and a half or three hours to reach the glacier. In fact, it was more like four and a quarter. I hadn’t accounted for the extra half hour from the car to the trailhead and I clearly didn’t account for this hike being so high. I knew I’d be climbing 1,500′ feet, but I guess I wasn’t accounting for the trailhead being at 10,500′. It took me about 40 minutes to climb from the tarn at 11,400′ to my picnic spot beside the glacier at 12,000′. I never stopped for longer than it took to snap a photo or two, but I wasn’t exactly breaking any land speed records.

I took only a short break at the glacier. My last few hikes were short enough that I had the luxury of stopping where I wanted for however long I wanted. As it was already a bit past noon when I got to the glacier, I had to be concerned with the weather. Being right below the Divide, you can find yourself in a thunderstorm with no warning.

I was back down a bit below the tarn when it started sprinkling. The summits above me were becoming slightly obscured by a white veil: the rain had turned to graupel. This forced me to don my hoodie and by now I was happy to think I’d made the correct choice of the hoodie over the microspikes.

On the hike down from the tarn to Isabelle Lake, I could watch the progress of the rain clouds as they blew to the east. I never got more than a slight sprinkle (and the graupel), but it looked like somebody downwind was getting a good shower.

Just before regaining Isabelle Lake, I ran into a few hikers heading up. None of them intended to try for the glacier. One said something to the effect that Isabelle Glacier isn’t a real glacier. I was about to protest when she said that she used to live in Alaska. Certainly, Colorado glaciers are nothing like Alaska ones, so I could see her point. I told her how much I’d seen Andrews glacier shrink in the last forty years and wondered how much bigger Isabelle was back then.

I took a short break at the outlet of Isabelle Lake. The stream flows under a large snowfield here, that was visible momentarily from the trail below. Clouds obscured the sun and the wind kicked up but I packed the hoodie away and stowed the poles. It took me an hour and a half to get here from the car on my way up, then two and a half hours to get from here to the glacier. Given that I don’t hike down these trails any faster than I hike up them, I figured I could be back to the car by 4:30.

Overall, I found it a most satisfying hike. The section up to Lake Isabelle isn’t very strenuous. Hikers wishing to go no further can find excellent places to take in the views just above the lake. There are scenic cascades and lake views, surrounded by dramatic mountains. And, for those willing and able, Isabelle Glacier is worth a visit.

No time-lapse video for this hike. Instead, here’s a larger-than-usual slideshow.