The morning’s fishing had been less than stellar, and as burgers sizzled on a small portable grill, I concerned myself with all the reasons to travel out here that weren’t connected to trout. For one thing, it was a beautiful day. The sky overhead was singularly blue and the banks were a botanist’s dream; the air was cool and comfortable, the fabled southwest Alaska wind nonexistent, and in the middle of it all, the river sparkled like a diamond in a coal mine.

I’d seen a sow grizzly and her two cubs not an hour beforehand. Just fifty yards away, a bald eagle sat perched upon a cottonwood, scanning for an easy meal. And earlier that morning, lurking deep in the mist that slowly drifted away from the surface of the water, I’d watched a bull moose take his last sips before disappearing into a fortress of willow and alder that abutted the river. Even after he was long out-of-sight I could hear the sharp crack of branches underfoot and the knock of velvet-wrapped antlers marking his passage.

As the average days of a year go, this one obviously offered a lot to be thankful for.

The trout, however, were as scarce as humility at a fly-casting competition. And while I took a moment to run a finger over my leader, checking for nicks, and then wrung the water from the deer-hair mouse attached at tippet’s end, I couldn’t help but remember that fish were indeed the most compelling reason for me to be here. I even thought about ditching the mouse for a sink-tip and the ugliest streamer I could dig out of the box. Luckily, lunch intervened, and by the time I’d dispensed with the burger, a bag of chips, an apple, and a Pepsi, self-control had gotten the better of me.

Like any angler who’s traveled a decent bit, I’m well acquainted with the notions of a slow start, of failure, of outright disaster. A lot of the time these spectacles of catastrophe are the products of oversized expectations, and eventually, most of us learn to modulate our hopes for an expedition lest even the most successful trips turn sour in our minds over some silliness like trout that won’t rise for a dry fly. At other times, it’s just the nature of travel. After all, even the most celebrated journey of exploration in the history of the American West had its low moments.

I’m talking about Lewis and Clark and the Corps of Discovery, of course, that hardy group of travelers and their two indefatigable explorer-captains, all of whom damn near starved to death once they moved out of the Rockies, where elk and deer had been abundant, and began to traverse the largely treeless expanse of the Great Columbia Plain. They were ultimately saved by trading with the Nez Percé for edible roots and some dried fish. Right after, most of the men were stricken by rather severe bouts of dysentery.

I think of them pushing on through the canyons of the Snake River, making what time they could in the rude dugout canoes they’d fashioned from the Ponderosa pines found along Idaho’s North Fork Clearwater. From Clark’s journal, we know spirits were low; Lewis, as it turns out, was so down he’d stopped writing altogether, but as every American schoolboy has learned, they soldiered on. I think of what they must have thought after first reaching the Columbia, where the fastidious note-taker Clark noted that the salmon were impossibly thick.

Totally unprepared for the encounter, both Lewis and Clark decided these fish, probably fall-run Chinook, were dying from disease. The Natives of the Pacific Northwest—among them the Yakima, Wanapam, Walla Walla, and Chinook—certainly knew better. To them, all life was interconnected. They hadn’t traveled as much or witnessed the diversity of ecosystems as the two great explorers, but they had seen enough with their own eyes to know their world depended on an annual invasion from the Pacific.

Far to the north, where I had just finished my lunch and was currently contemplating the chain of events that had delivered my fly into the willows behind me, the species of Pacific salmon are at least comparably vital.

As all who’ve journeyed through the region already know, Alaska’s southwest presents an angling setting almost without equal. The rolling lowlands are laced with a Who’s Who of the state’s best trout water and nearly all of these famous rivers and streams either begin or end in lakes that cradle hundreds of millions of juvenile salmon. In fact, for the last 4,000 years or so, the area has been home to some of the world’s densest concentrations of fish. Both the region’s wildlife and the riparian habitat that rises up from the muskeg rely completely on the salmon, the sockeye in particular. The millions of dead fish that remain in rivers after spawning add to the nutrient base of the water system. This affects nitrogen levels, which in turn aid the growth of algae, a source of food for zooplankton. Plus, during the migrations, while on the spawning beds, and even afterwards when the last of their energy wanes, the salmon are a tremendously important source of sustenance for the entire food chain: bears and other mammals, fish, and birds, each of which does its part to further spread the life-inducing nutrients. Realistically, the sow and her cubs I’d seen earlier, as well as the rainbows that had been snubbing my best presentations all morning long, could have up to 80% or more of their body weight traced back to the annual returns from the Pacific.

All of which combined to beg the question: Why in the hell was I using a mouse?

I had egg imitations in a small box in my left jacket pocket, and in the pack I wore around my waist there was a good group of fry patterns left over from opening week in Katmai. In Box Big-and-Nasty I carried at least twenty streamers shaded in white, chinchilla, gray, black, olive, or brown and any of them would have looked fishy enough to draw a take. In all honesty, I suddenly felt like a guy boiling up a batch of roots for dinner while sitting ten feet from a thriving salmon stream.

But then, for the second time that day, I remembered there were more reasons for travel to southwest Alaska than just the trout, and from somewhere behind the cobwebs that covered most of what I’d learned in fifth-grade history, I recalled there were times when persistence paid off in the biggest of ways.

I stuck with the mouse and forgot about trout. Later I was rewarded with two rainbows so small I didn’t even bother with the camera, and a sunset as stunning as it was unexpected.