I follow a blue thread on my atlas. The line labeled "Clark Fork" appears to end at Lake Pend Oreille. To confirm it, I turn from my atlas to my computer and consult Google, Wikipedia, the Clark Fork Coalition's website. I feel guilty; it seems like cheating to use a computer screen to learn about the water that flows two blocks from my apartment.

I try to recall how I learned about the rivers in Wisconsin, but I've forgotten the details. I don't remember when I learned into what the Namekagon flows or where the Amnicon empties. I take it for granted that, in my home place, I just know.

In Missoula, I learn new names: Rattlesnake, Sentinel, Clark Fork. But naming places is not entirely satisfying; naming them is not the same as knowing them. Naming them is not familiarity -- familiarity like family.

Place-sensitivity: I don't feel in place unless I understand my place. I didn't expect to be disoriented in this way. I remind myself, you've only been here a month.

In July, one month before I move to Missoula, my dad and I make a campfire on a spit of sand at the mouth of the Amnicon River in northern Wisconsin. We've been here many times. Before us, Lake Superior swells into beach pebbles. Sunset oranges flush the sky behind Duluth. The Amnicon flexes like a muscle where it joins the Lake.

Our fire's glow intensifies against settling darkness. A group of young people emerges on the river's opposite bank. One of them shouts that they are from a local summer camp. They build a fire, and a counselor leads a discussion to orient the campers from other states.

"What's out in front of us?" she asks. "Lake Superior." The campers know something about the area.

"What's that line of orange lights to our west?"

"Duluth."

"What's that river next to us?"

The campers shift on their logs, no answer.

The counselor enunciates the name slowly: "Am-ni-con. That's the Amnicon River. Have any of you ever been here before?"

Someone must ask what she means by "here."

"Right here. Right at this beach. This is the only place in the world where the Amnicon River meets Lake Superior."

Trudging along switchbacks on my fourth hike up Mount Sentinel, I stop to catch my breath more often than usual. I have a cold. I am tired. The three-quarter mile trail to Missoula's famous "M" wilts me. When I reach the concrete letter on the mountain, I crouch down, feet to earth, knees bent. I call on deep energy to catch my breath. My nose is running, and my cheeks are hot. Pressure drives dull pain into my temples. My head is swollen, too heavy to hold up. I start to fall forward, and I lean into my hands for balance.

I hold Mount Sentinel for a minute, two minutes, before my balance returns. I can lift my head and keep it raised. I could be waking from sleep. I become aware of the scene around me, sound by sound. Wind rushes. Crickets trill. Dry grasses rustle. Gravel crunches under me as I rise and steady my footing.

As I study Missoula from above, my gaze falls on a river I recognize. The Clark Fork -- bold blue, reflecting clear sky -- moves down below. I have not seen where it meets Lake Pend Oreille, but I know that even as it's flowing here, it's going there.

I'm flowing here, too. This is the only place in the world where I'm standing, right now -- the only place in the world where the Clark Fork flows through Missoula, Mont.

Lauren Koshere, a freelance writer based in Washington, D.C., is a 2012 graduate of the environmental studies M.S. program at the University of Montana.