CHEYENNE, Wyo. (AP) — A window-rattling late winter storm brought blizzards, floods and a tornado across more than 25 states Wednesday, stretching from the northern Rocky Mountains to Texas and beyond.

"This is a very epic cyclone," said Greg Carbin, chief of forecast operations for the National Oceanic and Atmospheric Administration's Weather Prediction Center. "We're looking at something that will go down in the history books."

In Colorado, a state patrol officer was hit and killed by a car as he was helping another driver who slid off Interstate 76 near Denver.

Corporal Daniel Groves, 52, w...