As the sun peeks over the eastern horizon to tease the towering green ash and black walnut trees shading my garage in Billings, I ease out the clutch to back my tired Nissan pickup from the driveway. It's 5:36 a.m. On the seat beside me, Gabe, a canine companion of uncertain breeding, has already begun to pant. His breath stinks. I momentarily consider shoving him into the rear with my backpack. But he's too smart for that. Sensing his master's indecision, he catches his breath and my gaze with his intelligent, irresistible brown eyes. I crank down the window instead. The breeze it affords is refreshing, but noticeably warm for this time of the day. It's going to be hot.
But not where I'm headed. Cave Lake, an alpine tarn in the Crazy Mountains, is perched in a lofty cirque at 8,638 feet above sea level. I'll be well into the mountains by noon, hiking through cool stands of Douglas fir and across pastures of springy alpine grasses at timberline. As Montana's largest city fades in the rearview mirror, I conclude with certainty that I'm among its dozen most sapient citizens.
Eight hours later, it seems a more reasonable assumption that the village has lost its idiot. The trek from the trailhead to Cave Lake spans roughly eight miles. I say "roughly," because unless you record your first route on a GPS and religiously follow it the second time around, you'll never tramp twice on exactly the same trail. It's about four miles to the confluence of Milly Creek, the goodly freshet that drains Cave Lake, and Sweet Grass Creek, the namesake watercourse for the maintained trail winding up its lush valley. It's around another four miles to the lake, this segment sans trail and significantly steeper.
Mid-afternoon finds the pooch and I on the north side of Milly Creek, on a vertiginous slope sporting more shifting scree than shady evergreens or spongy alpine vegetation. The canted, south-facing slope feels more like an oven than heaven. "Hellish" is a most appropriate term, not only for my parched, cracking lips and the sweat soaking my bandana and oozing freely from the underside of my backpack, but also for the blisters building on the soles of my feet encased in overheated rubber. The dog suffers as well. He tiptoes gingerly across the heated rocks, his salivating pink tongue hanging nearly to the upper joints of his forelegs. As we grind up the drainage, he learns to pick his way from patch to patch of soil and vegetation, waiting for his owner to scramble across the scree.
Dusk finds us at the lake at last. Unknown to me, Billings has set an all-time record temperature of 108 degrees. In the high country, the hottest days of summer often spawn its wildest storms. Up here, the pent-up energy of the inferno manifests itself in dark, boiling thunderheads and savage bolts of lightning. Just as I secure the fly to the tiny, one-person tent, the heavens deride a huddling human and prostrate dog with a deluge of immense raindrops driven by wind gusts that also whip misty sheets of water from the lake. An exceptionally potent bolt of lightning stabs into the flinty shoulder of the peak above the lake, dislodging a rockslide whose smashing course reverberates stridently around the cirque. We're a half-mile from the slide and safe. But what on earth are we doing here?
The answer to that question lies in the watery depths of Cave Lake and the pockets and pools along Milly Creek for a quarter-mile below the lake's outlet. Within them lives a trout whose Latin name rolls from your tongue in a drunken slur though you're cold sober. Golden trout, oncorhynchus mykiss aguabonita, are some of the most rare and resplendent salmonids in all of North America. For Montanans, they're one of the few California transplants welcomed to the state.
Endemic to the Kern River drainage, a watershed sequestered in the bowels of the Sierra Nevada mountains, golden trout were first presumed by biologists to be kissing kin of the Colorado River cutthroat. Vividly hued like goldens during the spawning season, in colors of crimson rather than gold, Colorado River cutthroats are exceedingly beautiful fish as well, sharing many similarities with goldens in physiology and appearance. However, more recent genetic analysis has shown that golden trout are more closely related to rainbows, a species with which they interbreed freely.
Lovers of cold, clear water with a quirky spawning style and life cycle, golden trout are found only in high mountain lakes and streams. While lacustrian (lake-dwelling) trout typically spawn in inlet streams, goldens prefer the outlets, to the effect that the fry emerging from eggs are flushed haplessly downstream. The best golden trout habitat is thus an alpine lake with another tarn below it, connected by a stream navigable to fish. After the eggs hatch, the fry are flushed into the lower lake, where they mature, then migrate back upstream to their parents' abode.
Goldens don't compete effectively with brook trout, and their genetic purity is quickly lost in habitats where they consort with their rainbow cousins. Hence, these aquatic nuggets of the Treasure State thrive in just a few high, specialized drainages that match their spawning requirements and isolate them from other trout.