By Tom Sentner

The deep, emerald green lakes on the west slopes of Glacier National Park are mysterious to me. It amazes me that lakes so high in elevation could be so deep, and that lakes so cold could be full of fish and insects. The unique color of the water leads me to peer again and again into the depths of lakes like Bowman and Quartz.

There is a genus of fish here, Salvelinus, which to my mind is swimming in mystery. Fish of the genus Salvelinus are char, the coldest of the cold-water fishes. Brook trout, lake trout, and bull trout are all technically char, not trout.

The advance and retreat of glaciers has left pockets of char in cold waters across the Lower 48 states. Brook trout, Salvelinus fontinalis, are native to the small rocky streams (or brooks) of the Appalachians. They can be found in pools so small they barely keep the fish wet, pools they share with giant hellbender salamanders in the misty, humid forests all the way down to the western Carolinas, ice-age remnants of the South’s cooler past.

Lake trout, Salvelinus namaycush, once supported commercial fisheries in the Great Lakes before overharvest. They are native to the Hudson Bay drainage of Glacier National Park, but were introduced into Flathead Lake, and from there have become invasive in the Columbia River drainage of the park. While in the Hudson drainage they co-exist with our native char, the bull trout, in the Columbia drainage they displace them.

Bull trout, the Salmon-Trout, so important for the cultures of the Crown of the Continent, are being displaced by a fish that was in turn displaced from its place in the Great Lakes Ecosystem.

Bull trout are the char of great western rivers and mountains. I spent the past summer in Glacier National Park learning about how the Anthropocene, the topsy-turvy and perhaps short-lived age of humans, has fish mixed up and bull trout on the brink. But what affected me most was actually seeing Salvelinus, a genus with DNA shaped by ice ages, in a land shaped by glaciers.

Tom Sentner is an aspiring nature writer and a second-year graduate student in the Environmental Studies program at the University of Montana. Years of odd jobs doing manual labor and environmental work have landed him in some strange situations in wide-ranging parts of the U.S., and he is now attempting to write about those experiences in the greater environmental context of our times. He is originally from Florida, but has also lived and worked in Illinois, Texas, and Washington State, and is greatly enjoying residing in Montana.