| Grant County | |
| Airport | 304-257-4435 |
| Ambulance | 304-257-1212 |
| Assessor's Office | 304-257-1050 |
| Fax | 304-257-4117 |
| Chamber of Commerce | 304-257-2722 |
| Circuit Clerk | 304-257-4545 |
| Fax | 304-257-2593 |
| Commission on Aging Family Services | 304-257-1666 |
| Convention & Visitor's Bureau | 304-257-9266 |
| County Commission | 304-257-4422 |
| County Clerk | 304-257-4550 |
| Development Authority | 304-257-2168 |
| Grant Comm | 304-257-2140 |
| Fax | 304-257-9028 |
| Health Department | 304-257-4922 |
| Grant Memorial Hospital | 304-257-1026 |
| Judges Office | 304-257-1737 |
| Magistrate Court Clerk | 304-257-1289 |
| Fax | 304-257-9501 |
| Magistrate Office | 304-257-4637 |
| Nursing Home | 304-257-4233 |
| Parks & Recreation | 304-257-1725 | Potomac Highlands Guild Behavioral Health Care | 304-257-1155 |
| Prosecuting Attorney | 304-257-2323 |
| Fax | 304-257-2593 |
| Public Library - Mt. Storm | 304-693-7504 |
| Public Library - Petersburg - Moomau | 304-257-4122 |
| Public Service District | 304-257-2377 |
| Sheriff's Office (Taxes) | 304-257-1818 |
| Fax | 304-257-2665 |
| Sheriff & Deputies Office | 304-257-2002 |
| Fax | 304-257-4987 |
| City of Petersburg | |
| City Office | 304-257-4944 |
| Police Department | 304-257-1100 |
| Wastewater Treatment Plant | 304-257-1127 |
| Water Plant | 304-257-4877 |
| Volunteer Fire Depts - Non-Emergency | |
| Maysville | 304-749-7731 |
| Mt. Storm | 304-693-7157 |
| Petersburg | 304-257-1122 |
| Schools | |
| Board of Education | 304-257-1011 |
| School Bus Garage | 304-257-4881 |
| Dorcas Elementary | 304-257-1220 |
| Headstart Program | 304-257-4853 |
| Maysville Elementary | 304-749-7441 |
| Petersburg Elementary | 304-257-1110 |
| Petersburg High | 304-257-1444 |
| South Branch Vocational School | 304-257-1331 |
| Union Education Complex | 304-693-7612 |
| WV State Government Offices - Local | |
| Department of Natural Resources | 304-257-4736 |
| Highway Department, Grant County | 304-257-4455 |
| Highway Department, District 5 | 304-289-3521 |
| Probation Office | 304-257-4545 |
| WVU Extension Office | 304-257-4688 |
| Workforce WV Employment Service | 304-538-7741 |
| WV State Police | 304-257-1411 |
| US Government Offices - Local | |
| Forest Service - Potomac Ranger | 304-257-4488 |
| USDA Farm Service Agency | 304-257-4702 |
| JR ROTC | 304-257-9319 |
| Social Security Administration | 304-257-2573 |