| Business | Phone |
| Thomas A Maddox 8933 Shady Grove Ct, Gaithersburg 20877 | (301) 330-0812 |
| Snider & Assoc 2 Professional Dr # 216, Gaithersburg 20879 | (301) 948-5100 |
| National Society-Pro Srvyrs 6 Montgomery Village Ave, Gaithersburg 20879 | (240) 632-8950 |
| Meridian Surveys Inc 811 Russell Ave # 303, Gaithersburg 20879 | (301) 721-9400 |