The river's name carries its own small mystery. John Sutter's militia captain Ernest Rufus is credited with naming it, but no one agrees on the origin. One theory traces it to the Pomo word Walali, meaning 'where the waters meet' -- an apt description for a river fed by three forks converging in the Coast Range. Another theory, stranger and less convincing, derives it from a mangled Spanish phrase: 'Que Agua Le La Ley,' roughly 'What Water Read The Law.' The river was previously known as the Valhalla River, a name it carried until sometime between 1877 and 1921 before the current name took hold. Whatever the etymology, the Pomo interpretation fits. The South Fork, the longest, runs northwest parallel to the coast. The Wheatfield Fork carries the heaviest flow, fed by Tombs, Wolf, House, Haupt, and Fuller creeks. The North Fork, the only portion in Mendocino County, angles southwest to join the others a few miles before the Pacific.

The Gualala does not merely cross geologically interesting ground -- it follows the San Andreas Fault itself. Both the South Fork and the North Fork trace the rift zone, their channels carved into the broken and uplifted terrain that the fault produces. This gives the watershed a paradox: the same tectonic forces that created the river's dramatic landscape also make it exceptionally fragile. The 298-square-mile watershed has a naturally high rate of erosion, the rock fractured and loosened by millennia of seismic activity. Human activity has compounded the problem. Logging roads, particularly Kelly Road between Lake Sonoma and Annapolis, funnel sediment into tributaries. The removal of streamside trees has raised water temperatures and eliminated the large woody debris that once created deep, cool pools -- the kind of pools that salmon and steelhead need to spawn.

Timber production has defined this watershed for generations. Three-quarters of the 298-square-mile drainage lies in Sonoma County, one-quarter in Mendocino, and nearly all of it is forested. Rainfall ranges from 38 inches at the coast to 70 inches inland, feeding dense stands of redwood and Douglas fir that have drawn loggers since the nineteenth century. Grazing once shared the landscape but has faded. The population remains sparse -- the community of Gualala, which depends on the river for its municipal water supply, is the only settlement of any size. For its last few miles, the river serves as the county boundary, a liquid border between Sonoma and Mendocino flowing through a narrow coastal canyon before meeting the ocean at a sandbar that shifts with the seasons.

Ric Davidge's 2002 proposal to bag Gualala River water was not idle talk. He planned to collect water from both the Gualala and the nearby Albion River, seal it in enormous marine bags, and tow it south to San Diego, a city perpetually short of fresh water. The plan had a certain audacious logic -- here was surplus water flowing unused into the Pacific, and there was a city of millions rationing every drop. But the Mendocino Coast saw it differently. Local opposition was fierce and immediate. The state legislature responded by passing laws requiring extensive environmental studies of the effects on fish habitat before any water-export scheme could proceed. The governor then signed legislation declaring both rivers recreational areas, effectively closing the door on Davidge and anyone who might follow. The Gualala would keep its water.