Access to banking remains a key hurdle for legalized marijuana operations as financial institutions remain fearful of dealing in a trade that’s still considered illegal at the federal level.

Some credit unions in Colorado, Washington and other legalized states do provide services to marijuana businesses. Other banks do so quietly. But many in the industry still operate largely—and dangerously—in cash.

California Treasurer John Chiang said the working group will discuss the idea of a public bank for marijuana businesses at its next meeting. In December, Chiang said he did not support the idea of creating a state bank solely to serve marijuana customers.