A grass fire southwest of the U.S. 287 and Northwest Parkway interchange in the southeastern corner of Boulder County has been contained to a haystack after burning 35 acres, and evacuation orders have been lifted. Lanes in both directions of U.S. 287 also reopened after a two-mile stretch had been closed for safety. All evacuations were lifted as of 4:30 p.m., according to Everbridge. The evacuation order had covered parts of Louisville and Lafayette extending to the southeast corner of Boulder County. Before it was contained, the fire was spreading east and northeast, according to Boulder County Sheriff’s Office spokesperson Carrie Haverfield. The blaze burned 35 acres, according to Mountain View Fire Rescue spokesperson Rick Tillery. Smoke billows from a grass fire near U.S. 287 and Dillon Road in Boulder County on Monday, Jan. 5, 2026. (Matthew Jonas/Staff Photographer) The fire was in a field west of U.S. 287 and south of the Northwest Parkway, but crews appear to have gotten it under control, Haverfield said. Earlier information indicated the fire was burning in Rock Creek Open Space, which is northeast of the U.S. 287 and Northwest Parkway interchange. Smoke from the fire had been visible from miles away. Lafayette Fire Chief Pete Bradshaw and Louisville Fire Protection District Chief Kevin Milan said that as of 5:30 p.m., ​there were still flames to be put out. Milan said the initial report was that the fire could have been started by a combine on part of the open space being leased to grow corn, but that is unconfirmed pending investigation, he added. Six fire agencies responded to the event with what Milan estimated to be “hundreds” of firefighters. “None of us are big enough to do it on our own,” he said. Bradshaw said Monday’s weather conditions were “similar” to the conditions that spawned the Marshall Fire in 2021 but, fortunately, less severe. “Certainly very similar,” Bradshaw said. “The wind wasn’t as severe from the firefighting perspective, but I’m sure from the residents’ view, it was a cold, windy, dry day, and those were all the things that were true at the time of Marshall. It just wasn’t the same intensity today.” Numbers for how many residents were told to evacuate are still uncertain, Bradshaw said, but he and Milan agreed that issuing the evacuation order was made to be better safe than sorry, and encouraged residents in the area to sign up for local emergency notification systems. Bradshaw and Milan said Good Samaritan Hospital was not affected by the evacuations. They said a fire weather watch is expected on Tuesday. The Louisville Fire Protection District, which led the response to the fire,  said in a Monday evening Facebook post that crews would remain on scene since the fire could continue to burn inside the haystack for the rest of the evening. The right southbound lane of U.S. 287, which had been closed, was reopened by 6:30 p.m., according to CDOT’s online trip planning map. ...read more read less