"They're the most underrated gamefish in North America," the guides told me. "Not even steelhead have their endurance, and no trout or salmon takes a fly so freely." That's high praise for the chum salmon (Oncorhynchus keta), also known as "dog salmon" because native Alaskans use the fish for dog food. The long, protruding caninelike teeth that male chums develop as spawning time approaches certainly contributed to the name.

With a range extending from South Korea to Siberia and Russia's Kamchatka Peninsula, and northern Alaska to Monterey, California, the chum has the widest distribution of any Pacific salmon. They enter most of Alaska's rivers, from the Arctic to the southeast, and travel great distances into the interior via the Yukon drainage. As a rule, however, they prefer low-gradient rivers and spawn within 50 miles of salt water.

Statewide, chums enter rivers as early as May and as late as December. Spawning usually takes place during the falling temperatures of late summer. The large eggs, typically 2,000 to 4,000 per female, hatch early the following spring. The fry immediately go to sea and remain there for from two to seven years.

The average Bristol Bay chum salmon weighs from 8 to 12 pounds and has been at sea for three years. River races can be distinct, extra large to atypically small, and so specific in their run timing that their upstream migration rarely varies more than a few days each year. Despite their widespread distribution, chum salmon haven't had much of a following among fly fishers until recently. The reason for this attitude can be best appreciated on many Canadian and Lower 48 rivers, where chums undergo their spawning changes (staging) before they enter their spawning rivers, and then spawn right at tidewater. They aren't handsome when they arrive in those rivers, and their appearance deteriorates rapidly. The opposite is the case on Alaska's Bristol Bay rivers. For many weeks, sexually immature, ocean-bright chums enter and ascend Bristol Bay's low-gradient rivers ready to take the full measure of those fly fishers who pursue them.

Trey Combs, author of Steelhead Fly Fishing and Bluewater Fly Fishing, is a Fly Fisherman contributing editor. He lives in Port Townsend, Washington.