| 1 | GRN | Edelweiss Holdings, Inc. d/b/a Rio Grande Air | IATA: E2, Callsign: Grande, IATA designator changed from 1I | USA | AVCODES |
| 2 | GRN | Edelweiss Holdings, Inc. d/b/a Rio Grande Air | IATA: H7, IATA designator changed to E2* | USA | AVCODES |
| 3 | GRN | Greenair | IATA: WK, | TR | AVCODES |
| 4 | GRN | Grande Aviation, LLC | Callsign: Grande, | USA | AVCODES |
| 5 | GRN | Rio Grande Air | IATA: E2 | | ICAO1 |
| 6 | GRN | Pinsly R.R. Co. | eliminated 4/1997 | | NAKINA |
| 7 | GRN | Carolina Piedmont Division, South Carolina Central R.R. Co., Inc. | added 7/1997; 7/2000; eliminated 10/2000; 7/2005 (not listed) | | NAKINA |
| 8 | GRN | Greenville & Northern Ry. Co., Inc. | 1/1975; added 4/1975; 1/1980-1/1994; eliminated 7/1997 | | NAKINA |
| 9 | GRN | Greenville & Northern Ry. Co., Inc. | 1/75; added 4/75; 1/80-1/94; eliminated 7/97 | | NRHS |
| 10 | GRN | Pinsly R.R. Co. | eliminated 4/97 | | NRHS |
| 11 | GRN | Carolina Piedmont Division, South Carolina Central R.R. Co., Inc. | added 7/97; 7/2000; eliminated 10/2000 | | NRHS |
| 12 | GRN | CAROLINA PIEDMONT DIV., SOUTH CAROLINA CENTRAL RAILROAD [PINSLY RAILROAD CO.; GREENVILLE & NORTHERN RAILWAY COMPANY] | | | PWRC |
| 13 | GRN | Greenville and Northern Railway | | | RSRV |
| 14 | GRN | Greenville & Northern Ry. Co., Inc. | | USA | TRAFFIC |
| 15 | GRNA | GRAINSTOVES INC | | | SCAC4 |
| 16 | GRNC | GREENE TRANSPORT CO | | | SCAC4 |
| 17 | GRNE | GARNER TRANSPORTATION INC | | | SCAC4 |
| 18 | GRNF | GRAND MAYFLOWER LLC | | | SCAC4 |
| 19 | GRNG | GRANGE SUPPLY CO INC | | | SCAC4 |
| 20 | GRNJ | GREEN, ARTHUR | | | SCAC4 |
| 21 | GRNK | GRANT TRUCKING | | | SCAC4 |
| 22 | GRNL | GRANE TRANSPORTATION LINES, LTD | | | SCAC1 |
| 23 | GRNL | GRANE TRANSPORTATION LINES LTD | | | SCAC4 |
| 24 | GRNM | GARZA RODRIGUEZ, NOE MARIO | | | SCAC4 |
| 25 | GRNN | GRENON, E W & SON INC | | | SCAC4 |
| 26 | GRNR | The Grand River Ry. Co. | 1/1975-7/2005 | | NAKINA |
| 27 | GRNR | The Grand River Ry. Co. | 1/75-7/2000 | | NRHS |
| 28 | GRNR | CP RAIL [GRAND RIVER RY.] | | | PWRC |
| 29 | GRNR | Grand River Railway | | | RSRV |
| 30 | GRNR | GRAND RIVER RAILWAY COMPANY, THE | | | SCAC4 |
| 31 | GRNS | GRAND SLAM TRUCKING INC | | | SCAC4 |
| 32 | GRNV | GREENEVILLE OIL & PETROLEUM INC | | | SCAC4 |
| 33 | GRNW | Great Northwest R.R. Inc. | 7/2005; added 4/2008 | | NAKINA |
| 34 | GRNW | GREAT NORTHWEST RAILROAD | | | PWRC |
| 35 | GRNW | Great Northwest Railroad | | | RSRV |
| 36 | GRNW | GREAT NORTHWEST RAILROAD INC | | | SCAC4 |
| 37 | GRNY | GREENBERG, MORRIS & CO INC | | | SCAC4 |
