A prescribed burn is underway at Hall Ranch near Lyons. Smoke may be visible north of Boulder.
Hall Ranch open space will be closed while approximately 40 acres are burned.
The Bitterbrush Trail, Nighthawk Trail, Nelson Loop, Antelope Trail and Button Rock Trail will be closed until fire personnel declare the area safe.
Boulder County Parks and Open Space and the Sheriff's Office Wildland Fire Management Program are conducting the burn. The goal of the project is to reduce hazardous fuels and improve wildlife habitat.