An ordinance allowing up to four medical marijuana dispensaries in the county, including two in West Marin, secured unanimous approval from the Board of Supervisors on Tuesday. The businesses, which will be able to deliver their goods, must be located at least 800 feet away from schools, youth-oriented facilities, smoke shops and other dispensaries. They will be limited to commercially zoned properties, making just 50 parcels in urban Marin eligible and just 134 parcels in West Marin. (The county has been without a single storefront dispensary since May 2014, when Corte Madera forced Marin Holistic Solutions to close.) In the next two months, the county’s Community Development Agency will propose fees and other criteria for the approval of dispensaries; by spring, it plans to start accepting applications. “There is a competitive process that will be followed, and the county will look for the best site, the best operator and the best plan,” said Tom Lai, the assistant director of the agency. The ordinance will also help the county prepare for a landmark state law passed in October that will provide state oversight and regulation of medical marijuana, including mandatory state licenses for growers, distributors and operators. County-approved operators will be able to apply for the state licenses, Mr. Lai said. In addition to concerns about proximity to homes, multiple speakers at a public hearing that preceded the vote on Tuesday called for the county to give preference to locally based operators. Lynette Shaw, who ran the Fairfax-based Marin Medical Alliance until it was shut down by the federal government, hopes to apply for a new license to reopen; however, she said she had trouble finding a location because eligible spots had been “taken up by out-of-towners” hoping to win a license. At the hearing, Mr. Lai said he had heard “great ideas” from the public and that there will be a public discussion about proposed criteria for applicants in the coming months.