(KPAX) 2:55 p.m. The Montana Department of Natural Resources and Conservation (DNRC) reports that a grass fire in the Waterworks Hill area of Missoula has burned approximately four acres.

DNRC spokesperson Kristen Mortenson tells MTN news no structures are threatened at this time.

Mortenson said a DNRC helicopter has made numerous bucket drops to stop the spread of the fire.

The Missoula City Fire Department is investigating the cause of the fire.

Initial report (1:51 p.m.) Crews are battling a grass fire that is spreading quickly in the area of Waterworks Hill in Missoula.

The fire is kicking up smoke that can easily be seen from Interstate 90 near the Orange Street exit.

The flames are moving uphill quickly to the north and east.

A helicopter has been called in to assist in the firefighting efforts.

The Missoula Fire Department is asking that people avoid the area.