On days when haze hangs around the valleys in Marin, Mt. Tam appears more distant as it projects only an outline, like an unfinished painting. On days like that memory has to give the relief of wooded slopes and gnarled rocks to the flat outlines of the mountain husked of definition.
Air Quality in the Bay Area
In the Bay Area, as in the entire state of California, a certain amount of air pollution comes from stationary industrial sources, such as refineries and power plants. But a greater percentage of harmful air emissions come from cars and trucks, construction equipment, and other mobile sources. California has more cars per household (1.8) than any other state, along with a thriving business economy and a continually expanding population. All of these factors contribute to the state and regional air quality challenges. – from the Bay Area Air Quality Management District‘s website [emphasis added]