ABSTRACT
The Lake Tahoe Thresholds Study has been of considerable interest in California and Nevada, as well as within the Tahoe Basin itself, partly because no one knew what a threshold was. The visual quality of the Lake Tahoe Basin is one of the main attractions of the region. Large areas of the basin in public ownership still offer natural landscapes of exceptionally high quality. Legislators from both states have long recognized the problem, and Congress in 1959 developed the Bi-State Compact, an agreement that provided the Tahoe Regional Planning Agency with powers to oversee development and conservation on all private lands in the basin. A Forest Service task group in 1971 evaluated the scenic quality of all the travel routes in the basin. Particulate matter in the basin of less than ten microns in diameter is produced chiefly by residential wood combustion, construction activities and vehicular traffic.
