Anytime you hold an organized event on BLM controlled land you need a permit whether it is a hotair balloon race, ORV event or rockhounding. Because your organized hunt will include BLM controlled lands you need to get permit, if a person is not involved in a organized event no permit is needed.
The PM Hunt and Convention ran into this a couple years ago and went to the BLM and showed that there was no organized hunting or prizes and the permit was waved.
