Someone must have had a reason for naming Treasure Mountain as they did. From what I can tell, surrounding mountains and Treasury Mountain next door actually hold the goods. Treasure Mountain is geologically responsible for the booty, though, and maybe some old-timer figured that out and named it appropriately.

It’s a challenge to walk through the mountains and not think about geology. Those who know nothing of mountains walk and wonder. I’ve heard them speculating about what this is or how that got there. I almost never go hiking that someone doesn’t ask me something about rocks.

“What are you collecting?” I asked the girl I’d caught up to on the trail. I’d spent the day scratching around for mineral specimens; I had collecting on my mind.

“Nothing, really,” she answered. “I’m just looking for a bookend. Do you know what this stuff is?”

Girl, you don’t know the half of it. “Yeah,” I answered, “it’s called hornfels.”

“Oh,” she sparkled, “are you a geologist?”

“Well…,”

“I have a question,” she pressed, “when a river enters a standing body of water, does it form a delta, alluvial fan or flood plain? I’m taking a geology class online.”

“Think Mississippi River and Delta Dawn,” I told her.

Hornfels isn’t worth much, probably better suited as doorstop than bookend. The rock is sharp and hard, forming angles and edges. It is rough stuff to walk on, as anyone who has hiked to Yule Pass can tell you. Piled up, hornfels makes good mountains.

And mountains, of course, can make for fun geology. The mountains around Crested Butte are some of the most geologically well-endowed mountains in the Southern Rockies. This profligacy is bad because it is responsible for stuff like molybdenum that big mining companies want to dig out from under Mt. Emmons. But the geological extravagance is good because it makes every hike a journey of exploration.

I wasn’t walking Yule Pass trail to collect hornfels. Instead, I was walking with friends who intended to climb Treasure Mountain. I thought I’d accompany them to the saddle, and then peel off and check a spot that I knew hosted nice, cubic fluorite crystals, sometimes artfully embedded in quartz. It is interesting stuff to a rockhound; pretty ho-hum to most everyone else. So be it; mystery and revelation are where it’s at.

We made good time to Yule Pass. Hiking behind Debbie Sporcich is like walking behind some kind of hiking machine. I usually like to take my time, kick a few rocks over the edge, smell the lupines and take pictures. But I was grateful for the incentive to get wherever we were going quickly. No lollygagging, no dawdling.

Furthermore, Yule Pass trail had improved considerably since I had hiked it. Last summer I encountered spots where soil and scree that held the road had washed off the bedrock and into the valley. Mounds of debris a thousand feet below testify to accelerated erosion. But material has washed down from above off Treasury as well, and somehow filled in enough to sustain a trail. That’s good thing, since straightforward Yule Pass access to the high country is a value.

The high country I was heading for doesn’t have a name; it’s just a place on a ridge. At about 13,000 feet, the ridge provides a great view of the back side of Purple Mountain. A couple of snowfields with respectable vertical swept down below the summit pyramid. We could see skiers earning late August turns; through my envy I considered that hell of a long way to haul ski gear.

Looking north across Crystal Canyon, Snowmass and Hagerman Peaks stand grey and stark against the horizon. Closer, Treasure Mountain Chimneys drop from the long ridgeline summit. Bear Basin reveals the top of Treasure Mountain Dome, and I was able to see a place I call Pleistocene Canyon. Bear Basin is visceral, primitive and primeval, practically perfect. I could hear the trolls grumbling down there among the granite.

Treasure Mountain is big, and one of those places you have to hike down to where you begin hiking up. That isn’t too bad in the morning when I’m fresh, but in the afternoon, tired from the day’s effort, hiking back out is a labor.

True to my plan, I used the time my friends spent reaching the summit to scrabble through the steep scree looking for fluorite. At first I thought I’d get skunked, but the gods smiled and I found my shiny rocks.