MANITOU SPRINGS, Colo. (AP) — Searing, record-setting heat in the interior West is making it harder for firefighters to battle wildfires in Colorado, Utah and other Rocky Mountain states.

Nearly a week of 100-plus degree days and low humidity in Colorado is sapping moisture from timber and grass, creating a devastating formula for volatile wildfires across the state.

Much of Colorado, Nevada, Utah and Wyoming are under a red flag warning, meaning conditions are hot, dry and ripe for fires. And the scorching heat in the region doesn't appear to be letting up soon.

In northern Colorado, a fire has scorched more than 130 square miles and is just 55 percent contained. An Alaska wildfire between Mount McKinley and town of Anderson grew to more than 30 square miles Monday. But firefighters have a nearly 70-square-mile fire near Ruidoso, N.M., 90 percent contained.