Correction Appended

UTKHOLOK RIVER BIOLOGICAL STATION, Russia — The wild salmon still rush the dark Utkholok and other rivers here in Kamchatka, one of the last salmon strongholds on earth. They surge in spring and come in pulses for months, often side by side in run after run.

All six native species of Pacific salmon remain abundant on this eastern Russian peninsula, scientists say, appearing by the tens of millions to spawn in its free-running watersheds. Even in October’s chill they come: coho and a trickle of sockeye, mixed with sea-run trout and char.

Now, in a nation with a dreary environmental record that is engaged in a rush to extract its resources, the peninsula’s governments are at work on proposals that would designate seven sprawling tracts of wilderness as salmon-protected areas, a network of refuges for highly valuable fish that would be the first of its kind.

Encompassing nine entire rivers and more than six million acres, the protected watersheds would exceed the scale of many renowned preserved areas in the United States. Together they would be more than four times the size of the Everglades, nearly triple that of Yellowstone National Park and slightly larger than the Adirondack Park, which is often referred to as the largest protected area in the lower United States.