Six charged in plot to import marijuanaRALEIGH (AP) - Six men, including one from North Carolina, have been charged with conspiracyto import at least 800,000 pounds of marijuana from Columbia since the spring of 1976 in an $1.8 billion smuggling operation, a federal prosecutorsays.The men were charged in a federal indictment unsealed late Tuesday afternoon in U.S. District Court in RaleighAssistant U.S. Attorney R. Daniel Boyce said investigators in “Operation Mayflower*’ had estimated that 'more than 1.5 million pounds of ^marijuana had been either seized from or connected to the smugglingorganization. The haul amounts toabout $1.54 billion in currentwholesale value, Boyce said He said the organization was based in North Carolina, Florida and Virginia and purchased the marijuana from unnamed sources in Col-mhMi.Among those charged in the indictment was Durwood Wayne Stone, of [Spring Hope, N.C.