“Our frustration and confusion over your administration’s uncalled-for attacks on state-authorized medical marijuana providers was best summed up by John McCowen, the chair of the Mendocino County (CA) board of supervisors, who said, ‘It’s almost as if there was a conscious effort to drive [medical marijuana cultivation and distribution] back underground. My opinion is that’s going to further endanger public safety and the environment – the federal government doesn’t seem to care about that,’” the groups wrote.