The eventual plan is for them to shut down the Mankato and Marshall Districts Communication Centers and consolidate to Rochester, so perhaps, they are using MSP Rochester. The only other thing i can think of is that they would use the PSAP of the county they are in. Troopers can do the vast majority of their work via mobile data terminals and MSP's CAD system is a universal for all troopers statewide.
If they are using MSP Rochester, they would remain on their local dispatch talkgroup and instead of MSP Marshall talking to them, it would be MSP Rochester on the MSP Marshall talkgroup.