Salmon are not native to the Tanana in the way that resident species like grayling are.

They are anadromous — they spawn in the river, migrate to the ocean, and return to the river to spawn again after years at sea.

The salmon runs are seasonal, predictable in their timing and location, and enormously productive when they occur.

A community that knows when and where the salmon will arrive, and that has the means to harvest and process them in large quantities, can store enough protein to survive the winter months when other resources are scarce.

This pattern — the exploitation of salmon runs as a core component of the annual subsistence cycle — is one of the most characteristic features of northern and northwestern North American Indigenous economies.