Here is Princeton's FSS information:
FSS 3 Letter ID: PNM
FSS Name: PRINC
Information Update Date: 01 MAR 2000
Associated Airport Site Number: PNM
Airport Name: PRINCETON MUNI
Airport State: MINNESOTA
Airport Latitude: 45-33-35.524N
Airport Longitude: 093-36-29.578W
Facility Type: AFSS
Facility ID/Voice Call: PRINCETON
FSS Owners Code: FAA
FSS Owners Name: FEDERAL AVIATION ADMIN
Operators Code: FAA
Primary Frequencies Used: 121.5 122.2 122.O 255.4
Hours of Operation: 24
Status of Facility: OPERATIONAL-IFR
Weather Radar Available: Y
Enroute Flight Advisory: YES
Flight Watch Hours: 0600-2200
PNM Telephone Number: 763-389-5880
Remarks: 1 VHF DF AVBL FOR HAYWARD WI LCTD LAT 46-01-11N/LONG 091-27-05W.5F2 VHF DF AVBL FOR BEMIDJI-BELTRAMI CO ARPT LCTD LAT 47-30-00.3N/LONG 094-56-00.0W.5F3 VHF/DF AVBL FOR BRAINERD-CROW WING CO/WALTER F. WIELAND FLD LCTD LAT 46-23-43.9N LONG 094-08-18.3W.5
They are the Flight Watch station for the Dakotas and most of the great lakes area. The Flight Watch RCOs are located in AXN,GFK, MOT, JMS, DIK (

), ABR, PIR, HON, ONL, FSD,FRM,SUX (

), GRI, OMA, FGT, EAU, GRB, MQT, DLH
Whew!
Here is Huron's info:
FSS 3 Letter ID: HON
FSS Name: HURON
Information Update Date: 05 AUG 2002
Associated Airport Site Number: HON
Airport Name: HURON REGIONAL
Airport State: SOUTH DAKOTA
Airport Latitude: 44-23-06.722N
Airport Longitude: 098-13-42.753W
Facility Type: AFSS
Facility ID/Voice Call: HURON
FSS Owners Code: FAA
FSS Owners Name: FAA
Operators Code: FAA
Primary Frequencies Used: 121.5 122.1R 122.2 122.6 243.0 255.4
Hours of Operation: 24
Status of Facility: OPERATIONAL-IFR
Weather Radar Available: N
Enroute Flight Advisory: NO
HON Telephone Number: 605-352-3806
Remarks: 1 DF OTS INDEFLY.5F
They are not a flight watch station.
And Fort Dodge...also not a flight watch station.
FSS 3 Letter ID: FOD
FSS Name: FORT
Information Update Date: 04 MAR 1998
Associated Airport Site Number: FOD
Airport Name: FORT DODGE REGIONAL
Airport State: IOWA
Airport Latitude: 42-33-05.242N
Airport Longitude: 094-11-33.184W
Facility Type: AFSS
Facility ID/Voice Call: FORT DODGE
FSS Owners Code: FAA
FSS Owners Name: FEDERAL AVIATION ADMIN
Operators Code: FAA
Primary Frequencies Used: 121.5 122.2 122.3 243.0 255.4
Hours of Operation: 24
Status of Facility: OPERATIONAL-IFR
Weather Radar Available: Y
Enroute Flight Advisory: NO
FOD Telephone Number: 515-955-8114
Remarks: 1 VHF/DF AVBL FOR LAMONI IA LCTD AT LAT 40-35-42NLONG 093-57-44.12W.5F2 VHF/DF AVBL FOR BURLINGTON IA LCTD AT LAT 40-46-42.14N LONG 091-07-33.52W.5F5 VHF/DF FOR LAMONI IA OTS INDEFLY.5F6 VHF/DF FOR BURLINGTON IA OTS INDEFLY.5F
Looking at the chart, it looks like you're right in the moose knuckle of Princeton, Fort Dodge and Huron. It also looks like there is a LOT of uncontrolled airports with approaches. It's possible the FSS folks spend a lot of time on the phone with the center coordinating IFR departures. I know they were pretty understaffed when the FAA was running the show, and I haven't heard a lot of good things about them since Lockheed Martin took over.