A FORMATION OF 5 SMA FLEW THROUGH A TEMPORARY RESTR AREA WITHOUT CLRNC. ERROR ADMITTED. DESIGNATED MOUNTAINOUS TERRAIN. NMAC BY INTERCEPT ACFT WITH RPTRS.

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ON JUL/XX/96; I FLEW 6 PAX FROM BOULDER CITY TO MARBLE CANYON. 3 OTHER PLTS AND MYSELF THEN RETURNED TO BOULDER CITY WITH ZERO PAX. THE FOLLOWING STATEMENTS ARE A DESCRIPTION OF THE FLT. SINCE I FLY THIS AREA AND RTE OFTEN; I WAS AWARE OF FOREST FIRES IN THE AREA ALONG OUR RTE. THE FIRES HAD BEEN BURNING FOR QUITE A FEW DAYS. I KNEW RESTR AIRSPACE HAD BEEN IMPLEMENTED FOR THE AREA. WE CHKED THE NOTAM WITH FSS. THE RESTR AREA DESIGNATED R- 4806 COVERED THIS AREA OF THE KAIBAB NATIONAL FOREST. IT WAS MY UNDERSTANDING THE RESTR AREA WAS 2000 FT AGL AND BELOW. THE WAY WE INTERPRETED THE SURFACE MAP; THE FIRE SEEMED TO BE AT AN ELEVATION OF SLIGHTLY LOWER THAN 6500 FT MSL. THEREFORE; THE 3 PLTS AND MYSELF BELIEVED 8500 FT MSL WOULD KEEP US CLR OF THE RESTR AIRSPACE R-4806. AS WE FLEW ACROSS THIS AREA; AT APPROX 8500 FT MSL; WE MONITORED THE AIR RECON FREQ OF 123.05. OUR COMPANY HAD BEEN COMMUNICATING WITH THE FORESTRY SVC IN THE AREA THE PREVIOUS DAYS OF THE FIRE. ON THIS DAY; THERE SEEMED TO BE NO ONE ON FREQ; OR IN THE AREA. JUST AFTER WE CLRED THE AREA; A CESSNA 340 BEGAN WEAVING IN AND OUT OF OUR 4 PLANES. I WOULD ESTIMATE IT CROSSED FRONT OF MY FLT PATH BY A DISTANCE OF 80-90 FT HORIZ. IT WAS CLOSE ENOUGH FOR MY ACFT TO FLY THROUGH ITS WAKE TURB. HE THEN PROCEEDED TO PULL UP TO MY 8 O'CLOCK POS AT A DISTANCE OF APPROX 40-50 FT. THIS IS WHEN I REALIZED I HAD PROBABLY INTRUDED ON R-4806. UPON RETURNING TO BOULDER CITY; MY COMPANY INFORMED ME OF MY VIOLATION. MY ERROR IS IN THE INTERP OF THE R-4806. I DID NOT REALIZE 2000 FT AGL INCLUDED THE RISING TERRAIN OF THE KAIBAB PLATEAU WHICH RISES UP TO APPROX 8300 FT MSL. HAD I REALIZED THIS; I WOULD HAVE FLOWN AT 10500 FT MSL AND THERE WOULD HAVE BEEN NO PROB. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTRS WERE ALL FLYING CESSNA 207 ACFT IN A VERY LOOSE FORMATION. THE FAA GAVE EACH OF THEM A LETTER OF WARNING. MOST OF THE RPTRS HAVE MOVED ON TO OTHER JOBS. SUPPLEMENTAL INFO FROM ACN 340293: A NOTAM HAD BEEN ISSUED STATING R-4806 WAS LOCATED AT THE GCN VOR 332 DEG RADIAL 42 DME POS FROM THE SURFACE TO 2000 FT AGL; THEN OUT TO A RADIUS OF 15 MI. I HAD THEN FOUND THE APPROX LOCATION OF THE CTR OF R-4806 AND DETERMINED THE ELEVATION TO BE ROUGHLY 6500 FT MSL. I MEASURED 2000 FT AGL ABOVE THE CTR AND DETERMINED THAT AN ALT OF APPROX 8500 FT MSL WOULD BE SUFFICIENT TO REMAIN CLR OF THE AREA. A TWIN CESSNA SETTLED LESS THAN 20 FT OFF MY L WING. SUPPLEMENTAL INFO FROM ACN 340128: I DEPARTED THE MARBLE CANYON ARPT (L41) #3 OF 5 ACFT.