Larimer County Sheriff Justin Smith says his lawsuit challenging marijuana legalization in Colorado was not spurred by his own beliefs on pot, but is instead meant to clarify a "quagmire" of conflicting state and federal laws.

"I always tell people, take marijuana out of it and put anything else in there, and look at the constitutional issue of, 'are we going to continue with the principle of federal supremacy?'" Smith told the Coloradoan Thursday morning.

Smith is the lead plaintiff in a federal lawsuit filed Thursday that challenges the state's legalization of recreational marijuana. In it, he argues that being tasked with upholding Colorado's constitutional amendment puts him in direct conflict with the U.S. Constitution and federal law.

"We're to protect the rights of individuals in our state," Smith said. "… By defending the right of those individuals (to possess and consume marijuana), it means violating federal law."