FLC OF AN MLG LANDED AT NIGHT AFTER TWR CLOSURE WHEN SNOW REMOVAL EQUIP WAS ON THE RWY. ARPT POLICY ADVISED CREW THAT A NOTAM WAS ISSUED EARLIER REGARDING PRIOR LNDG APPROVAL NECESSARY.

Narrative

TKOF FROM GFT DIRECT MSO. AFTER LEVELOFF AT FL220; I PROCEEDED TO TAKE OUT MSO MAPS; CHARTS; SEND ACARS ARR MESSAGE; PREPARE LNDG DATA AND MAKE PA'S. I ATTEMPTED TO RECEIVE MSO ATIS; HOWEVER; IT WAS TOO BROKEN TO UNDERSTAND. I THEN ATTEMPTED TO CONTACT MSO UNICOM WITH NO RESPONSE; I THEN PULLED UP WX FOR MSO ON ACARS; IT WAS 5 MINS OLD AND NOW INDICATED 1 3/4 MI -SN. DSCNT CLRNC TO 15000 FT AND 10000 FT RESPECTIVELY WERE RECEIVED FROM ZLC. ALSO ATC INDICATED HE WOULD TRY AND GET A BRAKING ACTION RPT FROM THE COMMUTER WE WERE FOLLOWING. WE HEARD THE BRAKING ACTION RPT FROM THE COMMUTER AND IT WAS POOR. THIS WAS RECEIVED JUST PRIOR TO APCH CLRNC BY ATC. APCH CLRNC WAS GIVEN BY ATC AT APPROX 22 MI FROM MSO WITH INSTRUCTIONS TO CALL ONCE ON THE GND ON THIS FREQ. AT THE OM THE AUTOPLT DID NOT CAPTURE THE ILS (FO FLYING) AND IN ADDITION THE FO HAD A STEER FLAG IN VIEW ON HIS ADI. I TOOK CTL OF THE ACFT AND FLEW THE APCH TO LNDG. THE FO INSTS RETURNED TO NORMAL SOMEWHERE AFTER GS CAPTURE. GND LIGHTS WERE IN VIEW SOMEWHERE AROUND 5-6 MI AND THE RWY CLEARLY IN VIEW AT LEAST BY 3 MI. AT THIS TIME I STATED 'IS THAT AN ACFT ON THE RWY; XMIT IN THE BLIND AGAIN THAT WE'RE LNDG.' AT APPROX 2 MI I STATED 'IT MUST BE SNOW PLOWS.' WE COULD SEE A MOVING RED LIGHT TOWARD THE APCH END AND WHITE MOVING LIGHTS TOWARD THE DEP END. THE LIGHTS DEPARTED THE RWY AND WE LANDED WITHOUT INCIDENT. BRAKING ACTION WAS POOR. ON BLOCK IN WE WERE MET BY AN ARPT POLICEMAN AND HE STATED HE WANTED TO SPEAK TO US; WHICH WE AGREED TO. HE STATED 'WE DID NOT HAVE PRIOR APPROVAL TO OPERATE INTO MSO AS PER A NOTAM POSTED 1 1/2 HR PRIOR TO OUR ARR.' WE STATED THAT WE HAD NO SUCH NOTAM IN OUR PAPERWORK. (I RETAINED THE DEP PAPERS.) ALSO; WE HAD NO INDICATION THAT SNOW REMOVAL OPS WERE IN EFFECT. THE ARPT POLICEMAN REQUESTED MY LICENSE AND MEDICAL AND COPIED DOWN THE INFO. LATER THE POLICEMAN STATED THAT HE WAS MANNING THE RADIO AND IS NOT FAA/ATC TRAINED OR QUALIFIED; AND THAT HE FELT IF THE FAA IS NOT GOING TO MAN THE TWR THEN THE FIELD SHOULD BE CLOSED FOR OPS DUE TO THE SAFETY PROB. I AGREE. THE MSO AGENT REPULLED UP OUR NOTAMS FOR MSO AND NO REF TO THE 'STATED/REQUIRED' PRIOR PERMISSION WAS INDICATED IN OUR SYS. WE ACTUALLY ARRIVED APPROX 15 MINS EARLIER THAN SCHEDULE. OUR MSO STATION AGENTS HAVE OUR OUT; OFF; AND EON TIMES. AT A MINIMUM THAT SHOULD BE COORDINATED VIA PHONE TO THE ARPT AUTH (GND PERSONNEL). THIS SEEMS TO ME AS A MINIMUM FOR SAFE OPS INTO NON OPERATING TWR ARPTS. SINCE WE ARE A SCHEDULED CARRIER; OUR TIMES ARE KNOWN BY THE STATIONS. ACTUAL ARR TIMES ARE ALSO KNOWN. IF PHONE COORD IS NOT POSSIBLE THEN I RECOMMEND NO OPS INTO THESE ARPTS; ESPECIALLY DURING THESE CONDITIONS. ALSO ZLC DIDN'T ADVISE OF SNOW REMOVAL OPS IN MSO.