Just after 2:30 p.m. Sunday, crews were dispatched to the area of 21 E Knollwood Dr., the same location they responded to a fire less than 24 hours ago.
When they arrived, officials say about one acre of grass was on fire.
They say the dark and heavy smoke came as a result of burning in an area of cattails and emergent vegetation. Yesterday and today's fire are still being investigated, but believed by officials to be of human cause.
Jim Bussell, Rapid City Fire Department, says "Because of favorable weather conditions, a good number of resources on scene, and a good box around it and what I mean by that is we have good fuel break all the way around, the crews decided to take advantage of that and do some hazardous fuel reduction in the form of a burnout so they intentionally set fire to some of the area and burned that out to square it up.
Approaching winter, the fire department reminds people that we're in a period of significant drought, and asks people to be cautious while using sources of ignition.