From USPSA
The USPSA Nationals that were scheduled to be held October 11-17th at the Cameo Shooting Sports and Educational Complex in Palisades, CO have been rescheduled to the CMP Marksmanship Park in Talladega, AL.
After the recent 2 Gun Nationals that were held at the Cameo Range, The Colorado Parks and Wildlife that operates the state run facility implemented new procedures with regards to an affidavit for "Compliance with the Law" Declaration that all competitors would have to, under perjury, complete. USPSA made the decision to refuse to participate in this and choose to reschedule and relocate Nationals.
The real meaning is that you would have to swear you are not bringing full capacity and extended magazines to Colorado.