Colorado Gov. John Hickenlooper signed legislation to approve a plan to establish a co-op banking system for marijuana dispensaries, essentially creating the world's first financial system for legal weed sales. If the Fed doesn't shut it down first.

The Associated Press reports Hickenlooper officially signed the bill into law Wednesday morning. The law will establish a network of uninsured co-operatives where marijuana dispensaries can pool their money and receive simple banking services, pending approval from the Federal Reserve.

Since January 1, when Colorado started legally selling marijuana, fears have arisen about the large sums of cash kept on hand at dispensaries. Major banks have refused to offer simple banking services to marijuana dispensaries because the sale of marijuana is still illegal, federally. Dispensaries have been forced to do business almost entirely in cash, with little oversight or protection. Local politicians worry these large sums of money — the state has earned almost $12.6 million in tax revenue since the beginning of the year — make dispensaries ripe for thieves. 

Whether or not the bill can secure the finances flowing through the state, which recently came under fire from anti-legalization activists, is now in the Federal Reserve's court. When state legislators voted on the bill in May, the Federal Reserve was not expected to approve the plan