Don Brunell

Today’s news is filled with images of the massive wildfire that has raged across nearly 400 square miles near Yosemite National Park, threatening San Francisco’s water supply.

The Yosemite wildfire started Aug. 17 in the Stanislaus National Forest when a hunter’s illegal fire swept out of control. To date, it has burned nearly 250,000 acres of timber, meadows and sensitive wildlife habitat and cost $100 million. Officials say it will cost tens of millions of dollars more to repair the environmental damage.

Federal officials have amassed a team of 50 scientists, more than twice the usual number...