There is a Federally Licensed Raptor Rehabilitator in Pierre. She operates All Creatures Veterinary Clinic, and operates the rehab facility at her home. If there is a Federally-licenses rehabber near Sioux Falls, that would be a lot closer to Mitchell.
The Fish and Wildlife Service Special Agents should be notified ASAP anytime an injured raptor is located, given that the US Attorneys Office is in the middle of a large prosecution concerning Eagles. I help Maggie with transport to Pierre. I always have a cover letter stating why I am in possession of a raptor, and my transport destination. Maggie always is in contact with Fish/Wildlife personnel. Awhile back, I took a male Bald Eagle to Pierre. Fish/Wildlife were consulted on every step.