DENVER — (CNN) In Colorado, there’s $66 million of marijuana tax money at stake in Tuesday’s election.

That’s how much the state collected from taxes on legal marijuana sales over the first year. But a quirky law in the state constitution means that all that money may go right back to taxpayers.

Here’s what happened: When Colorado voters said “yes” to legalizing marijuana for everyone 21 or older, not just medical patients, they also voted to approve some extra taxes: Growers pay 15% when they sell to retailers and consumers pay 10% at checkout.

The state pulled in $66 million from those taxes, which is actually less than initially projected.

Overall, Colorado’s tax revenue was higher than expected last year. And according to a state law, that means that the state has to refund the money collected from any new tax — in this case, the pot tax. It would only happen this one time.

Legislators wanted to give voters a choice about whether that actually has to happen, putting it to a vote in Tuesday’s election.

Coloradans can vote “yes” if they want the state to keep the money. About $40 million of it is slated for school construction. That’s in addition to $24 million for schools already received thanks to the pot tax. Most of the remainder will be used to pay for enforcement and treatment programs outlined in the legislation.

But if the ballot initiative is voted down, the $66 million will be refunded to taxpayers. But don’t expect a check in the mail.

The money will be disbursed three ways. Part of it will go back to taxpayers through an income tax credit, which averages about $8 per person. Another chunk will go back to marijuana growers, who will be refunded for the 15% tax they paid last year. The rest will go back to customers, who will enjoy a lower tax on legal weed they purchase starting in January and continuing until the remainder of the money (about $17 million) is refunded.

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