The Lewstone Fire, which was first reported on August 22 and forced evacuations, is burning northwest of Fort Collins near Laporte, 3.5 miles west of Highway 287.
The chief said Monday that "People representing a number of different ideologies showed up at the demonstration armed with various weapons, body armor, and a clear desire to incite violence.
The post says the investigation is continuing and more arrests are expected. According to the post, several of the people arrested are career criminals
Police in Fort Collins say several people have been charged in connection with the investigation into the shooting of a 17-year-old male earlier this month