A wildfire burning near a small mountain town in southwestern Colorado nearly doubled in size over the course of two days this week, causing containment to drop and forcing dozens of homes to evacuate a month after lightning first started the blaze. The Elk fire has charred 6,213 acres , or nearly 10 square miles, just outside of Lake City in Hinsdale County, fire officials said in an update Saturday morning. Forty-two structures in the San Juan Springs subdivision north of Lake City are under mandatory evacuation because of the fire. The entire town of Lake City, home to approximately 400 people, is also on a pre-evacuation warning. The mandatory evacuation zone includes San Juan Springs, Rocky Springs, Silver Springs and Eagle drives; Elk Road; and Deer Trail.