Boulder could begin a prescribed burn at Shanahan Ridge as soon as Tuesday, as the city hopes the 85-acre burn will help improve forest ecosystem heath. The burn could take place sometime between Tuesday and the end of the month and will only be conducted if the weather and vegetation conditions are right, officials said. Ignition would only begin after 10 a.m. on the day crews choose to start the burn. Whenever the city does begin the operation, residents in south Boulder will see smoke from the fire that could linger for several days. The burn area itself is near the South Shanahan Fork, Bluestern Connector and the Big Bluestern East trails.