You may be able to pre-register with the Colorado GOP at

The County Parties facilitate the caucuses. They must:
-Provide and prepare venues for each precinct caucus.
-Train PCP’s and volunteers to run each meeting and to manage the larger venues where several precincts will hold their meetings.
-Create lists of registered Republicans in each precinct for check-in and meeting records.
-Create packets with meeting instructions, donation envelopes, record-keeping forms, candidate information and proposed resolutions for each precinct.
-The PCP’s may hold pre-caucus get-togethers for caucus attendees to become acquainted.
-The county party may be able to provide a walk list for someone who would like to campaign for PCP or Delegate prior to the caucus. (Visit and click on Directories to find information about your county party. Consider volunteering!)