The list I have was taken from active license info from the FCC website as licensed to PSE. I have no idea if it was 3rd party contractors or not, but no others share the licenses in the area. It was definitely for line repairs.
As taken from this site (RadioReference.com):
Puget Sound Energy (MPT-1327)
This system is deprecated, and may no longer be in use or is superseded by another system.