Yes.. there is a cutoff for a tag for a specific unit, once that happens you can buy an OTC. I believe how it works is that Getting an OTC gets you 1 turkey, getting a tag for a specific unit gets you a second turkey.
I?ve seen turkeys off Peak to Peak Highway for what its worth.. Always see them along the river bottoms on float trips along the Colorado and the Gunnison as well. I?ve waken up many times in a tent along the Colorado with a flock of turkeys around my tent.
I filed for a specific unit and it gave me an option that if I didn?t draw that unit that they would just send me an OTC tag.