The Logging That Almost Killed the Lake

The forests you see around Lake Tahoe today are not the forests that were here in eighteen sixty. Most of what you are looking at is second-growth, replanted or naturally regenerated over the last century and a half. The original trees, sugar pine and Jeffrey pine and white fir, old growth, very old growth, were cut down between approximately eighteen sixty-two and eighteen ninety-nine. They were cut down because Virginia City needed wood.

The Comstock Lode silver mines of the Virginia City area required timber in industrial quantities: beams for mine shafts, lumber for pump houses, trestles for ore rail systems, boards for the expanding city itself. The Tahoe basin's forests were the nearest large source. They were felled, floated across the lake, transported by flume down the eastern slope, and cut into lumber at mills throughout the basin. By eighteen ninety, contemporary observers noted that the slopes were bare. Photographs from that era show it clearly.

The consequences arrived slowly. Bare slopes meant more water running off faster, carrying fine particles of silt into the lake. Those particles do not settle quickly. They stay suspended. They reduce clarity. Researchers at the University of California Davis have been measuring Lake Tahoe's clarity every year since nineteen sixty-eight using a simple tool: a black-and-white disk lowered into the water until it disappears from view. In nineteen sixty-eight, the disk disappeared at approximately one hundred two feet. By the early twenty-twenties, it was disappearing at around sixty-two feet. Forty feet of clarity, lost over six decades, its origins traceable to a decision made in the eighteen sixties to strip every tree off a mountain range to feed silver mines.

The forest grew back. The watershed's memory of what was done to it has not fully cleared.