DURANGO, Colo. (AP) - Several wildfires continue to burn in southwestern Colorado, where dry conditions are expected to continue into next week.Air tankers and helicopters were again helping fight the 201-acre Vallecito wildfire on Friday. It's burning on land burned a decade ago by the Missionary Ridge fire. The residents of 18 homes have been warned to be ready to evacuate if the fire spreads toward them.Fire managers originally thought it started on Tuesday but now believe it's been burning since Oct. 12, last Friday. Lightning is believed to have started it.Meanwhile, the Goblin Fire, which has been burning in the Weminuche Wilderness since early this month, is estimated to be between 600 and 700 acres. Authorities have determined that it was sparked by the Durango & Silverton Narrow Gauge Railroad Train.