THE HELICOPTER, C-GNMJ, CRASHED ON A FRZN RIVER AS MINERS WERE BEING TRANSPORTED FROM THE JOHNNY MOUNTAIN GOLD MINE (NEAR THE U.S./CANADIAN BORDER) TO WRANGELL, AK. THE PLT COULD NOT RECALL THE ACCIDENT & THE SURVIVING PASSENGER (PAX) REFUSED TO BE INTERVIEWED. ANOTHER HELICOPTER WAS EN ROUTE FROM WRANGELL TO THE MINE SITE AT THE SAME TIME. THE PLT OF THE OTHER HELICOPTER MADE 2 ATTEMPTS TO PENETRATE THE BACK SIDE OF THE SNOW SQUALL & FAILED. AFTER REVERSING COURSE TO RTRN TO WRANGELL, THAT PLT SIGHTED THE WRECKAGE OF C-GNMJ. PASSENGERS WHO HAD FLOWN TO WRANGELL ABOARD C-GNMJ ON A PREVIOUS TRIP SAID THEY HAD ENCOUNTERED SNOW SQUALLS & WHITEOUT CONDITIONS. AT ONE POINT, ONE OF THE PAX BELIEVED THE HELICOPTER WAS IN A HOVER. HE SAID IT THEN CAME OUT OF THE SQUALL IN A STEEP BANK. A FORMER EMPLOYEE RPRTD THAT COMPANY OFFICIALS PRESSURED THE PLTS TO COMPLETE THEIR FLTS, IN SPITE OF MARGINAL WX CONDITIONS.