| Navaid Facility ID: | FSI |
| Official Navaid Facility ID: | FSI |
| Navaid Facility Type: | FAN MARKER |
| Navaid Name: | Trail |
| City: | FORT SILL |
| State: | OKLAHOMA |
| FAA Region: | |
| Latitude: | 34-46-52.945N (34.7814) |
| Longitude: | 098-24-08.296W (-98.4023) |
| Lat/Long Survey Accuracy: | NOS |
| Owner: | US ARMY |
| Operator: | US ARMY |
| Common System Usage: | Yes |
| Public Use: | Yes |
| Navaid Class: | LFM |
| Hours of Operation: | 24 |
| Magnetic Variance: | 3.6 E as of 9/30/2025 |
| ARTCC High Altitude ID (Name): | ZFW (FORT WORTH) |
| ARTCC Low Altitude ID (Name): | ZFW (FORT WORTH) |