These are listed on another website as nationwide.
U.S. Postal Service (USPS) Frequencies
Department Chan Frequency Tone Callsign Usage Notes
Output Input
USPS 164.7000 n/a 156.7 Truck-Transport
USPS 166.2250 n/a Main Post Office
USPS 166.2500 n/a Main Post Office
USPS 169.6000 n/a Main Post Office
USPS 170.1750 n/a Truck-Transport
USPS 408.0500 n/a Internl Ops.
USPS 409.2750 n/a 120.0 Operations
USPS 410.2000 n/a 110.9 Operations
USPS 414.7250 n/a 136.5 Lambert Field Ops.
USPS 418.3000 n/a 82.5 Security
USPS 1/2 414.7500 n/a 82.5 Postal Inspectors
USPS 3/4 415.0500 n/a 82.5 Postal Inspectors
USPS 5/6 415.4500 n/a 82.5 Postal Inspectors