Last week, Oklahoma and Nebraska sued Colorado, hoping the U.S. Supreme Court will rule that legalized recreational marijuana is unconstitutional due to its impact on neighboring states.

Colorado is marking one year since it became the first state to allow recreational pot sales. It was a year of highs and lows, as Colorado sought to figure out exactly how it should work, reports CBS News correspondent Barry Petersen.

If skeptics wondered about the popularity of pot, on January 1, Colorado residents answered with their wallets. Lines that first day stretched around the block.

But Colorado's governor, John Hickenlooper, who opposed legalization, was still skeptical when CBS News spoke with him in February.

"I think myself and almost every elected official in the state of Colorado, we didn't want to be the social laboratory, but our voters passed it by a large a margin -- 55-45," Hickenlooper said. "And we accept that this is going to be one of the great social experiments of the next 50 years."

Colorado now has more than 800 outlets. Denver alone has more pot shops than Starbucks.

John Hudak studies government policy at the Brookings Institution, which these days means watching marijuana trends.

"Well, there's clearly a profit motive among producers. They're not in the business just to deliver some public good in the form of marijuana," Hudak said. "At the same time, the states have found that there is a selling point around the taxation of marijuana that's an important part of passing these initiatives."

Indeed, selling pot is bringing in lots of tax revenue at both the state and local levels. The state took in more than $43 million in the first nine months, and local municipalities collected millions more.

But high times have come with some low points, like how to regulate edibles -- products like candy that are infused with marijuana.

It allegedly lead to the suicide of a visiting college student who overdosed and jumped to his death.

Some things evolved as the year went on, like testing. At the outset it was voluntary, which brought us to biologist Genifer Murray. She founded Cannlabs to examine pot samples. In some of the marijuana she's tested, she said she found mold, mildew and ecoli.

Four states and the District of Columbia permit pot for recreational use and more than 30 states allow sales for some form of medical use.

"What the success does show is a state could do this and the sky doesn't fall , that society doesn't fall apart or go into crisis," Hudak said.

On the contrary, it went classical. In Denver, the Colorado symphony made pot pay, raising money with bring-your-own-marijuana parties -- proof to pot proponents that Colorado's first year showed that the days of reefer madness have given way to marijuana going mainstream.