The question of what is commercial photography and when do I need a permit is a common question. The defining regulation for both the US Departments of Agriculture and Interior is Public Law 106-206. For still photography if you are in an area that is generally open to the public (i.e. overlooks, trails, developed sites, etc…) and you aren’t using props or models, then you shouldn’t need a permit. This same guideline applies regardless of if you are taking photos for fun, stock photos for resale, or any other project for sale. Keep in mind this is specific to still photography and if you are capturing video or audio, the rules are different and you may very well need a permit.
Excerpt from P.L. 106-206
Most parks (and other land management agencies) have personnel, or dedicated offices, assigned the responsibility to manage commercial filming and photography. If you have any questions, it is always a good idea to check with the land management agency well in advance. If you do need a permit, the process may very well take a while (1+ month) and is not a last minute or on site activity.
Patrick has been photographing in and around national parks for fun over the past decade. He now resides in Bozeman, MT and enjoys capturing the greater yellowstone.