Midwest
Wildlife Rehabilitation Center of Minnesota
https://wrcmn.org/
Wildlife Rehabilitation Center at Wisconsin Humane Society
https://www.wihumane.org/wildlife
The Iowa Department of Public Health
https://idph.iowa.gov/
Team Mojo WildRescue
https://www.teammojowildrescue.org
East
The Wildlife Center of Virginia
https://www.wildlifecenter.org/
Southeast
South Florida Wildlife Center
http://www.southfloridawildlifecenter.org/
Clinic for the Rehabilitation of Wildlife (CROW)
http://www.crowclinic.org/
Misc
https://squirrelforum.com/