| Defense POW/MIA Accounting Agency | Federal |
| CyArk | Non-Profit Organization |
| Crow Canyon Archaeological Center | Non-Profit Organization |
| Cornerstones Community Partnerships | Non-Profit Organization |
| Cornell University | Academic Institution |
| Conservation Science Partners | Non-Profit Organization |
| Commonwealth University of Pennsylvania | Academic Institution |
| Columbia University in the City of New York | Academic Institution |
| Colorado State University - Pueblo | Academic Institution |
| Colorado State University | Academic Institution |
| Colorado Mesa University | Academic Institution |
| College of the Atlantic | Academic Institution |
| College of Charleston | Academic Institution |
| Clemson University | Academic Institution |
| City University of New York | Academic Institution |
| Christopher Newport University | Academic Institution |
| Chief Dull Knife College | Academic Institution |
| Central Washington University | Academic Institution |
| Center for Natural Lands Management | Non-Profit Organization |
| Center for Large Landscape Conservation | Non-Profit Organization |
| Center for Coastal Studies | Non-Profit Organization |
| California Botanic Garden | Non-Profit Organization |
| Bureau of Safety and Environmental Enforcement | Federal |
| Bureau of Reclamation | Federal |
| Bureau of Ocean Energy Management | Federal |
