Until last September, Morrison had a group of patrons who organized the weekly football pools. He kept the pool cards and cash at the bar, but they managed the pool, he said.

Then Vargo sent him the letter explaining that it's a violation of state law to require a payment or purchase to participate in a pool and that it would be in "everyone's best interest for your business to bring its practices into compliance before there is an investigation or any formal action."

Since then, Morrison said he sought clarification on the law from Vargo’s office but never heard back, which means he doesn't like the odds of hosting a pool where participants put a certain amount of money on a square on a larger grid and then can win a prize if their number comes up during the game.

Rapid City Police Chief Steve Allender said his department rarely gets a complaint about sports pools and is not looking to make any football-pool busts.

"It's not something that gets reported, even on an occasional basis," he said. "To my knowledge, we don't have any investigations going on."

Vargo said he, too, is unaware of any business being prosecuted for a football pool but nonetheless wants them to be aware of the possible legal consequences.