Mt. Rainier's melting glaciers create hazard - Los Angeles Times As receding glaciers expose crumbly slopes, vast amounts of gravel and sediment are being sluiced into the rivers that flow from the region's tallest peak. Much of the material sweeps down in rain-driven slurries. "The rivers are filling up with stuff," Kennard said from his vantage point atop the pile. He pointed out ancient stands of fir and cedar now standing in water. Inside Mt. Rainier National Park, gravel-choked rivers threaten to spill across roads, overtake bridges and flood the historic park complex at Longmire. Downstream, communities in King and Pierce counties cast a wary eye at the volcano. As glaciers continue to pull back, the result could be increased flood danger across the Puget Sound lowlands for decades. "There is significant evidence that things are changing dramatically at Mt. Rainier," environmental consultant Tim Abbe said. "We need to start planning for it now." Similar dynamics are playing out at all of the region's major glaciated peaks, according to research hydrologist Gordon Grant of the U.S. Forest Service. Climate experts blame global warming, triggered by emissions from industries and cars, for much of the ongoing retreat of glaciers worldwide. North Cascades National Park has lost half of its ice area in the last century. Mt. Rainier's glaciers have shrunk by more than a quarter. "Every year it's been either bad or really bad," Kennard said. "This year it was really, really bad."