ON A MISSED APCH FROM JAC; SMT CLBED IN IMC ABOVE DESIGNATED MISSED APCH ALT.

Narrative

UPON REACHING THE JACKSON; WY; ARPT ON THE VOR/DME RWY 36 APCH; I DETERMINED THAT THE CLOUDS AND VISIBILITY WERE TOO LOW TO PERMIT A SAFE LNDG. I EXECUTED A MISSED APCH CLBING OUTBOUND ON THE R-014 FROM JAC VOR. I DECLARED A MISSED APCH AND RECEIVED NO RESPONSE FROM SALT LAKE CENTER. CENTER WAS VERY BUSY AT THE TIME AND HAD BEEN SLOW TO RESPOND DURING MY APCH PROC. I THEN CALLED BACK AND INDICATED THAT I'D LIKE TO CLB TO MEA AND PROCEED TO MY ALTERNATE AT RIVERTON (RIW). AGAIN; NO RESPONSE AND I ASSUMED; HOWEVER; THAT THEY HAD HEARD ME AND WERE SLOW AGAIN IN RESPONDING. THE PUBLISHED ALT FOR THE MISSED APCH IS 12000 FT TO NALSI AND THEN THE DUNOIR VOR AND HOLD. I CONTINUED CLBING THROUGH 12000 FT BECAUSE: 1) I THOUGHT THEY HAD HEARD MY REQUEST TO CLB TO MEA AND PROCEED TO RIW; AND 2) I WAS NERVOUS ABOUT BEING SO LOW AS 12000 AROUND DUNOIR; ESPECIALLY SINCE WHEN YOU USE THE ILS APCH TO JAC THEY ALWAYS HAVE YOU MAINTAIN AT LEAST 15000 FT XING DUNOIR. AS I WAS GOING THROUGH ABOUT 13500 THE CTLR CAME ON THE AIR AND TOOK ME TO TASK (COURTEOUSLY) FOR EXCEEDING 12000. HE THEN CLRED ME TO 15000 DIRECT RIW.