Last year a friend of mine posted some amazing pictures from a day trip she had made to Castner glacier. She shared photos of exploring an under-glacier ice crystal coated cave/tunnel that was simply amazing.
I’ve lived in Alaska since 1993 and was not even aware this glacier exists. The crazy part is that it is only a mile off the Richardson highway. During the summer there is a rough road that you can drive a half mile in and then it is only half a mile further to the glacier. During the winter as I discovered yesterday, it is an easy mile walk on a hard packed snow trail.
Last summer my family went camping with some friends and on one of the days we hiked into the glacier. The glacier is located 145 miles south of Fairbanks. During the summer, the glacier is not much to look at. In fact it is one of the least spectacular glaciers I’ve ever seen.
The terminus is on fairly flat ground and it is difficult to tell where the glacier ends and the valley begins. The surface of the glacier is covered in dirt, rocks, and in some places plants. While we explored the terminus last summer we discovered that what we thought were some hills at the foot of the glacier were actually dirt and plant covered ice. The glacier is melting and retreating and I’m sure the dirty surface is accelerating the process.
The cave that my friend share pictures of is a tunnel that carries meltwater out from under the glacier. Last summer when we hiked in we could not get close to the opening due to the huge flow of water coming out. In addition the ice surrounding the opening was covered in a layer of mud that terminate steeply in the fast flowing waters. Trying to cross this surface would have been deadly. We kept our distance, but I also knew I’d be back.
One of my goals this winter was to get back down to the glacier. I wanted to go late enough in the season that the outflow would still be frozen, the temperatures warming a bit, and the sun returned enough to light things up. I was hoping for a sunny day, but it is such a hard thing to predict.
I have this week off work and had planned on heading down by myself, but both of my two sons are out of school because of the virus and thought it sounded like a fun adventure and went along.
We left home at around 8 am under cloudy skies with a temperature of 20 F. The national weather forecast for the area around Castner glacier was calling for sunny skies but I had my doubts. After gassing up the truck, we headed down the Richardson highway towards Delta.
About thirty miles out of town we got our first good look at the mountains to our south and I was happy to see that they were in sun. Of course a few minutes later we drove into snow and it would not be until we got well south of Delta Junction that we would get out of the clouds.
We stopped in Delta Junction 100 miles SE of Fairbanks to top up the truck and pick up an early lunch. Then we got back on the road for the last 45 miles. I was hoping to start hiking no later than noon and we were on track.
If we had just driven straight through we would have easily gotten down to the glacier by 11 am, but the stretch of highway starting at Donnelly Dome about 15 miles South of Delta Junction and continuing for the next 50 miles I consider one of the most beautiful stretches of road in Alaska.
This 50 mile stretch of road heads into the mountains following river valleys up to Summit lake before starting the gradual decent back down towards Valdez far to the south. I knew I would not be able to drive through without stopping several times for photos. I’ve driven this stretch of road many times in the summer and fall, but this was my first time in the winter.
I made my first stop just to the East of Donnelly Dome. It is a very flat stretch of road with wide open sparsely vegetated land for miles around. In the midst of this flat stands Donnelly Dome rising close to 1,500 ft above the surrounding land.
As we came down onto the flats on our way past Donnelly Dome, I could see the edge of the clouds just to our south and a bit to our East, the sun shining through a gap, highlighting the foothills of the mountains below. I stopped and took several photos as did my oldest son.
We continued on south making stops along the way until we reached the Castner creek bridge. Parking was available to the south of the bridge where space had been cleared due to the high number of people heading up to the glacier this winter.
As we geared up the sun was shining, the temperature was around 20 F, and there was only a gentle wind. I say gentle, but it was still enough to strip heat away from us while we got dressed in warm gear. And gentle is relative. Compared to the winds that can howl through the area sculpting the snow and drifting across the road, it was gentle, but compared to what we get in Fairbanks it was strong.
My boys and I put on more layers than we probably needed and packed more in our backpacks before heading out. I also brought along my snowshoes, but my boys chose to leave theirs in the truck. I did not know what kind of trail conditions we would find but it turned out that the snowshoes stayed strapped to my backpack.
The trail into the glacier was hard packed snow about two feet wide and as long as we stayed on the trail there were no problems, but venturing off was another story. The depth of the snow was difficult to gauge due to drifting.
Some places we could see bare soil, other places just the tops of trees that could have been two feet or twenty tall. I did get off trail a couple times for pictures and mostly I stayed on top of the hard windblown surface, but a couple times I broke through and had a leg sink in up to my hips. As the day progressed, the surface became softer off trail and sinking in became more frequent.
It was about a mile hike up to the mouth of the cave at the terminus of the glacier. We had almost reached the mouth of the cave when we spotted the other hikers. They passed us and we continued on. Approaching the cave, it is not visible until you are right on top of it. It does not come out the exact front of the glacier, but rather off the side of a glacial lobe. Last summer, the approach was impossible due to the raging torrent of water exiting the cave. On this trip we had to hike down into the cave due to large drifts at the mouth.
At the mouth, the cave ceiling is about 20 ft overhead but slowly decreases as you walk further in until it is head height and then chest height. The ice surface was sculpted during the summer by flowing water into an undulating surface of concave indents butting up against each other separated by narrow ridges. On the ceiling the ridges are coated by ice crystals that the further in we walked grew larger and larger.
What I found most amazing was the fact that despite all the visitors, it did not appear that any of them had chosen to be destructive. When the ceiling dropped down to head and then chest height forcing us to bend over, the nearly foot long crystals that coated it in some areas, seemed completely intact.
The crystals were fragile enough that even gently brushing against them as happened several times was enough to bring them down. I am sure that they are continuing to grow and any inadvertent damage is over time repaired, but I was still struck by how intact the fragile formations were.
The boys and I spent around 30 minutes exploring the cave and walked several hundred feet in. We could have gone further, but did not feel like crawling as the cave roof came down. As we got deeper into the cve the crystals changed.
Close to the mouth of the cave the crystals appeared furry and soft, very pillowy. A bit further in they became blocky long spears, then a bit further in delicate needle like spears, and at the furthest point there was a shift to six sided large geometric formations. The pattern I saw resembles that which I’ve seen in smaller cracks on a grand scale. I am still not sure what conditions cause the differences in crystal formation.
I took a lot of pictures in the cave of the crystals, and while I had some come out nicely, none of them really do justice to the incredible formations we saw. I do not have the skill or equipment to capture great images under the conditions I found in the cave, but it is something I am hoping to get better at.
The hike out of the cave and back to the truck was rather uneventful. We passed a few more small groups of people making the trek up to the cave before we got back to the truck.
I don’t know if there are always this many visitors, or if it was because more people have time on their hands with the virus, but it seemed busy for a weekday. We did talk to one couple up from Palmer and some others that we talked to appeared to be foreign tourists.
We got back on the road around 2 pm and arrived back in Fairbanks close to 5 pm. I asked my boys if the hike and cave were worth the five hour round trip drive and both said yes.
It is not something I plan on doing regularly, but it is something I’d do again. We were lucky with the weather and I was very happy that both my sons chose to go down as well. My oldest is in college and it was a good opportunity to see a bit more of him, something we havn’t had since he moved into the dorms this past fall.