Getting your Trinity Audio player ready... PORTLAND, Ore.—Geologists have developed a new computer model to simulate the massive Lake Missoula floods that repeatedly carved the Northwest landscape ...

Floodwaters rise more than 1,000 feet as they slam into the Columbia River Gorge from the east. The torrent blasts through the narrows at 60 mph, carrying truck-size boulders and house-size icebergs.

Where the road dead-ends, a man and boy are casting lines. “Any luck?” I ask, my elbow out the car window as if to test the breeze. The creek is cloudy, the day overcast. “Just a few squaws.” The ...

Mount Jumbo rises above the University of Montana's Rankin Hall in Missoula. The lines on the mountain were carved by lakes created during the last ice age 13,000 to 15,000 years ago. When the ice ...