HIGH ALT FLT IN A LOWER PWR ACFT RESULTS IN A FORCED OFF ARPT LNDG.

Narrative

I DEPARTED THE ARPT IN MONTROSE; ON JUN/FRI/95 AT APPROX XA30 AM; IN MY CESSNA 150; ALONE. I FLEW E TOWARD MONARCH PASS; AND CLBED TO AN ALT OF 11500 FT. AS I APCHED MONARCH PASS; I TURNED STEEPLY TO AVOID IFR CONDITIONS. DURING THE TURN; THE ACFT BEGAN TO LOSE ALT. AN ATTEMPT TO LEVELOFF AND MAINTAIN ALT WAS NOT SUCCESSFUL. THE ACFT CONTINUED TO DSND AND A ROUGH LNDG WAS MADE ON A TURN OFF APRON ON THE S SIDE OF US HWY 50; APPROX 1/2 MI W OF MONARCH PASS. THERE WERE NO INJURIES. AFTER SECURING THE ACFT; I HITCH HIKED TO SALIDA ARPT WHERE I EMPLOYED AN ACFT MECH TO DISASSEMBLE AND TRANSPORT THE CESSNA TO SALIDA ARPT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR 'DOES NOT KNOW WHY THIS HAPPENED.' MAYBE HE WILL LEARN WHEN HE TAKES THE FAA PROFICIENCY CHK RIDE THAT HE HAS SCHEDULED. THE L WING WAS REPLACED; THE R WINGTIP WAS REPAIRED; THE L HORIZ STABILIZER WAS REPLACED AS WAS THE ENG MOUNT. THE RPTR FEELS THAT HE WAS 'LUCKY TO HAVE WALKED AWAY FROM THIS.' HE WAS RELUCTANT TO TALK ABOUT THE INCIDENT. HE STATES THAT THE C-150'S SVC CEILING IS 12500 FT AND HE WAS FLYING IN MOUNTAINOUS TERRAIN AND TRYING TO MANEUVER AT 11500 FT.