page 13 Colorado big game brochure;
Evidence of sex
1) It is illegal to have or transport a big game carcass without evidence of sex naturally attached. It is illegal only to have evidence of sex accompany the carcass.
2) Evidence of sex is;
A) Buck/Bull; Head with antlers or horns attached to carcass or testicles, scrotum or penis attached to carcass.
B) Doe/Cow; Head, utter (mammary) or vulva attached to carcass.
3) Heads detached from carcass are not adequate evidence of sex.
4) If a carcass is cut into pieces or deboned, evidence of sex only needs to be attached to a quarter or another major part of the carcass. All portions must be transported together.
I just leave the scrotum or one nut attached to the deboned quarter. You have to take a little time and be careful when you are skinning it out. That is usually enough for the wardens unless you run into some gungho young one.
What area are you hunting in?