Heavy equipment was moving in Thursday to supplement 100 additional firefighters brought in to help bottle up five fires burning in northwestern Montana along the Highway 2 corridor. Firefighter numbers grew to 307 Wednesday as they took advantage of relatively high humidity levels to tamp down the intensity of the fires. Those conditions allowed for backfires and new fire lines to be built on the largest of the two blazes. The 1,145-acre Lazier Creek Fire grew by only five acres Wednesday. It remains at 30 percent contained.