The Arctic Grayling (Thymallus arcticus) is a unique species of fish native to the upper regions of North America, including most of Alaska. Historically, they are native to only Michigan and Montana in the Continental United States, although they are now considered extinct in Michigan. The waters of southwest Montana still hold native Arctic Grayling, who are identifiable by their slender silver bodies and their large sail-like dorsal fins that are decorated with red and purple spots. They live in both rivers and lakes in southwest Montana, although river-dwelling populations have seen a significant decline in recent years. Despite this, anglers in Montana can still catch this unique and beautiful species.
Arctic Grayling are both fluvial and adfluvial in southwest Montana, meaning that they live in both rivers and lakes, respectively. Grayling spawn in shallow and fast-moving sections of rivers and streams, and many lake-dwelling populations move into feeder creeks to spawn. There are also populations of Grayling that both live and spawn in lakes. In general, though, Arctic Grayling are more migratory than most other species of fish. In the winter, they prefer deep and slow-moving sections of rivers, and in warmer temperatures, they move into faster runs. Individual grayling have been recorded to swim more than sixty miles of the Big Hole river during a season change. Like cutthroat and rainbow trout, Grayling spawn in the spring, usually sometime between March and June. Arctic Grayling are unique, though, in the fact that males reach spawning grounds before females do, fighting with each other for positioning. When the females arrive, the Graying begin to school, and they reproduce by broadcast spawning. In adulthood, Alaskan Grayling can reach lengths beyond 20 inches and weights over 8 pounds. In Montana, they are generally smaller, usually growing to lengths between 8 and 14 inches.
Arctic Grayling populations are threatened in the Continental United States. They have become extinct in Michigan, and have disappeared from much of their native range in the Upper Missouri River basin. Today, these fish exist mostly in the Big Hole River basin, and are most commonly found in some of the high alpine lakes around Bozeman and Big Sky. Anglers who target them are recommended to practice catch-and-release, as populations continue to decline each year in Montana’s waters. Despite this, fly fishing for Arctic Grayling can be one of the most rewarding experiences available in Montana’s beautiful wildernesses. In the summer, Grayling eagerly take dry flies, and can offer an exciting fight on a lighter-weight fly rod. The pursuit of them will also take anglers to some of the most astounding ecosystems in the United States. Their high-alpine lake homes generally require long and physically-demanding hikes to reach. Yet, the views from these places are spectacular, and the thrill of catching these gorgeous fish above treeline is unrivaled. So, lace up your boots, pack your fly box, and get ready for an epic Montana adventure; just remember to handle this amazing native species with care so that anglers can continue to appreciate their beauty for generations to come.