On Wednesday the United States’ first legal recreational pot sales began in Colorado, at 8:00 a.m. At least 24 shops in eight cities opened their doors in the state. Adults 21 and older are able to buy up to an ounce at the shops, or even grow their own.

Some store owners expected to sell out of their supply on Wednesday, and large lines formed.

One Colorado State University Study estimates that Colorado’s pot shops will bring in more than $600 million from more than 640,000 users this year, excluding tourists.

One of the first customers at a pot shop in Denver was an Iraq War veteran.

“Now I get to use recreational cannabis to help alleviate my PTSD and it’s a stepping stone for other states to help other veterans as well,” said Sean Azzariti.

Taxes on the marijuana will hit 25 percent on the majority of the state’s marijuana transactions.

Some supporters of legalization in Montana cite the possible tax revenue as a reason they would want to see legalization in their own state.

“All the money you’re going to save, making it so the courts don’t have to deal with it, the cops don’t have to deal with it, that’s going to be great,” said Missoula resident Erik Lillquist.

But NBC Montana also spoke with Montana residents who said the same law would bring negative changes to their communities.

A Washington State couple told NBC Montana they voted against the law in their own state. They said that’s partly because they think the law could lead to the floodgates opening for other harder drugs to become legalized.

Washington state’s pot shops are expected to open in the spring.

When discussing Colorado’s law, Calvina Fay of the Drug-Free America Foundation said “I think it’s going to be a huge disaster. I think it’s something that there will be so much damage done to the children out there, that it’s going to be difficult to undo it.”

Marijuana remains illegal at the Federal level, though the Justice Department has said that it won’t try to block the laws in individual states.