As a duly sworn law enforcement officer, I have to break it to you.... if I ask you for ID, you will need to produce it for me. If you can not or will not provide ID, I can consider you to be impeding my investigation and will take you to jail where you will be booked and through the use of fingerprints and other methods, we will attempt to ID you.
Trust me, I'm not out to violate anyones' civil rights, but you do have to provide identification should I request it during a lawful investigation. Typcially this ID will be government issued i.e. driver's license or state issued ID card.
Happy geocaching!
As a citizen, when I ask for your ID, are you required to present it?