VIDEO: The Dark Canyon fire nine miles northwest of Capitan has grown to 420 acres. The fire was ignited by lightning strike Aug. 4. The fire is in a remote part of the Smokey Bear Ranger District in the Lincoln National Forest near Tucson Mountain. There are no structures at risk and no active evacuations. Firefighters are using a technique known as backburning. "It involves setting a controlled fire in the path of the approaching wildfire," a Lincoln National Forest press release states. The fire is on Lincoln National Forest lands. The Dark Canyon Fire is the kind of low-intensity fire that was a normal part of the American southwest ecosystem. These kinds of fires happened every 10-35 years. Updates about the Dark Canyon Fire will be reported daily to InciWeb Incident Information System website and to New Mexico Fire Info website.