Note: This is a listing of deprecated systems. These systems are either no longer in use or have been superceded by another system.
| System Name | Type | Flavor | City | County | Updated |
|---|---|---|---|---|---|
| Airtel Wireless, LLC (UHF) | LTR | Standard | Billings | Multi-County [7] | 2016-08-02 |
| Akiyama and Associates (Montana) | LTR | Standard | Various | Gallatin | 2018-07-20 |
| Billings Public Safety | LTR | MultiNet | Billings | Yellowstone | 2013-02-05 |
| Dunne Communications, Inc. | LTR | Standard | Various | Multi-County [5] | 2016-08-02 |
| Great Falls International Airport | iDEN | Standard | Great Falls | Cascade | 2016-08-02 |
| NorthWestern Corporation | LTR | Standard | Butte | Multi-County [2] | 2016-08-02 |
| Phillips 66 Refinery | Motorola | Type II | Billings | Yellowstone | 2020-01-13 |
| Stillwater Mining Company | LTR | Standard | McLeod | Sweet Grass | 2016-08-02 |
| Teton Communications Systems (LTR) | LTR | Standard and Passport | Various | Multi-County [11] | 2022-02-02 |