YELLOWSTONE NATIONAL PARK, Wyo. (AP) — Yellowstone National Park officials say only one of six lightning-sparked fires showed widespread activity during dry weather but grew only a few acres and the blazes have not impacted park visitors.

Park officials say the 11-square mile Alum Fire showed intermittent smoke columns Sunday but lost energy at sunset. Officials say they expect a new weather pattern Monday with increasing humidity and wind and possible showers in the coming days.

The Alum Fire is one of six that make up the Druid Complex Fire burning north of Yellowstone Lake. The fires have burned 18.2 square miles. In recent days, the fires have been inactive or have not grown much.