January 1 will bring legal recreational marijuana to California, a cannabis cash cow that will make as much as $7 billion rain down on the state. But one problem with that torrential downpour of cheddar is that many folks in the industry won’t have anyplace to put all that cheese, except maybe under the mattress.

At a recent meeting of California’s Cannabis Banking Working Group, the merits of a public, state-backed bank that could be used by marijuana businesses was discussed, as reported by The Cannifornian. Because cannabis is still banned on the federal level, banks overseen by the federal government can’t directly do business with the cannabis industry.

Most legal cannabis businesses are forced to deal largely in cash. Some who attended the CCBWG meeting said they’ve resorted to carrying around duffel bags full of bills to do large business transactions, leaving them much more open to robbery than nearly any other legitimate businesses.

Members of the cannabis industry shared stories of how the lack of banking access has forced them to carry around duffel bags full of cash and held back their businesses.

The U.S. currently has only one public bank, the Bank of North Dakota, which largely works with farmers. A public bank like this one is backed by the state instead of the federal government, so the federal regulations which oversee most commercial banks don’t apply.

Cannabis insiders aren’t the only ones interested in a public bank either. Folks from outside the industry reportedly advocated for a public bank at the CCBWG meeting, citing a lack of trust in federally-run banks which may have caused the recession. Los Angeles and Oakland are both looking into creating their own city-backed banks, for use by both weed and non-weed businesses.

The idea, of course, is not without its downsides.  Kevin Klowden, executive director of the California Center and Managing Economist at the Milken Institute nonpartisan think tank, pointed out at the meeting that a state-run bank won’t stop federal agencies like the DEA from seizing cannabis money. “As long as the federal law says marijuana is illegal, they can go after it,” he said.