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Calaveras area firefighters are mounting a huge offense against a large wildfire in San Andreas today.
Investigators now say that fire was caused by a spark from a riding lawnmower.
CDF Tuolumne Calaveras Unit Spokeswoman Beth Ruano says containment of the 150-acre blaze on Mountain Ranch Road is expected tonight.
There are five air tankers, two helicopters, 13 handcrews, 16 fire engines and three bulldozers working the fire now.
