The US National Forest system turns 100 this year, as today’s San Francisco Chroniclereports. (The precise centenial birthday is either February 1 or March 3, depending on your intepretation of events.) The article focuses on policy changes in the Forest Service, which today faces a welter of pressures related to logging, forest fires, off-road vehicle use, grazing, watershed degradation, and invasive species.

National forest issues are critical to Cascadia. In fact, roughly half of the US portions of Cascadia are in national forest. That makes the Forest Service easily the largest land manager in the US Northwest. It also means that the long-term ecological prospects for Cascadia hinge, in large measure, on Forest Service policy.

By the same token, Cascadia is a vital component of the national forest system. Cascadia encompasses 45 percent of all national forest lands. Oregon, Washington, and Idaho collectively boast one-quarter of the nation’s total (and Idaho alone has about 1 acre in 9 of all Forest Service land).

A caveat: The figures above are this morning’s back of the envelope calculations. They’re roughly right, but they’re rough.

UPDATE: I made a numerical gaff earlier. Approximately 40 percent of the US Northwest is under Forest Service ownership, not half.