Got geology?
Scenery, wildlife, exercise, a sense of accomplishment, escape, photography, solitude, camaraderie, exploration, trail mix – All are legitimate reasons to go for a hike, but “geology” is another that I would add to the list. Being able to read a landscape, and understand the processes that caused it to take that form, adds another level of enjoyment to almost any hike I take. Geology was a major consideration as I planned a “first hike of the summer vacation” on the prairie 30 miles west of Great Falls. I had been curious about several landforms associated with an area of ancient volcanic activity (volcanic field), so I decided to go check them out. The formations, which include a cliff used by Montana’s first people as a buffalo jump and four small buttes, are all “intrusions” that formed as magma moved through cracks, pooled underground, and hardened (dikes, laccoliths, sills). Then, over tens of millions of years, the formations were exposed as less durable sedimentary layers above them eroded away. (More about this in the photo tour)

Laccoliths, Dikes, and Bears – Oh my!
This hike was on private land, so I obtained permission from a couple ranchers several days before setting off on the walk. I wanted to explore the buffalo jump before it warmed up enough for rattlesnakes to come out, and then walk a loop that included climbing each of the four buttes. So I left Helena at 4:45 am on a Saturday morning a couple days after school let out for the summer, drove the 85 miles, put my snake gaiters on, and started hiking. The kill site exceeded my expectations – It was much more impressive than the few developed buffalo jumps that I’d visited. From there it was onto Fishback Butte, which was also “interesting” – in a much different way. On the way down from the butte I was surprised to see a large bear about 100 feet away. It started huffing, and then began walking toward me. I didn’t expect to see a bear on the prairie, so I hadn’t packed bear spray. I wasn’t willing to play dead, and I know bears can climb trees, but this guy didn’t seem very ambitious – So I decided to climb the large, dead pine tree that stood behind me. From my perch 15 feet above the ground I watched as the bear slowly walked to within 50 feet of the tree, stopped to watch me for several minutes, and then sauntered on up and over to the other side of the butte.

Good medicine.
Once I was sure the bear was long gone, I climbed down and started the next leg of my journey, frequently looking over my shoulder as I walked toward Haystack Butte. Although nothing I saw or experienced the rest of the day could top the buffalo jump or the bear encounter, it was all good. This ended up being one of my most unusual AND most exciting hikes ever – “just what the doctor ordered” after 9 months of teaching high school science. Note to self: Bring bear spray next time.

FYI – Links, etc.
1. The photo tour includes photos of the bear, the buttes, the bison kill site, and maps too. Be sure to read the captions.

2. Because of the distance (21 miles) I rate this hike as “extreme”. I left Helena at 4:45 am and returned at 7 pm. Here is a map of the area. Once it opens you can zoom in or out, etc.

3. For those interested in learning more about “intrusive formations” (aka “plutons” or “plutonic formations”) here is a nice 3-step animation that shows how they form.

4. It is difficult to get permission to do this hike, but there is public access to Crown Butte (belongs to The Nature Conservancy) just a few miles away. A nice trail takes you up onto the butte’s west side. Once on top, the trail fades away, so you’re on your own from there. I will feature the Crown Butte hike later this spring (5-6 miles round-trip). In the meantime you might like to look through my Crown Butte Virtual Field Trip – does not open on many mobile devices.

5. Here is a Wikipedia page devoted to the ancient volcanic field that caused the buttes to form.