Washington breaks ground on two historic fronts this week when it becomes legal in this state for same-sex couples to marry and adults to smoke marijuana in their homes.

When voters passed Initiative 502, they opened the door for legal possession of small amounts of marijuana starting Thursday and establishment of a full-blown, state-licensed marijuana industry by 2014.

And in approving Referendum 74, voters upheld a law allowing marriage of same-sex couples that the Legislature adopted and Gov. Chris Gregoire signed earlier this year. Couples can obtain marriage licenses starting Thursday.

Grethe Cammermeyer and Diane Divelbess of Coupeville intend to be among the first applying for a marriage certificate when the Island County Auditor’s Office opens that day.

Cammermeyer, a nurse who served in the Vietnam War, earned the rank of colonel in the Washington National Guard. She earned national attention after her discharge in 1992 because of her sexual orientation. She successfully sued to overturn the ban on gays and lesbians in the military and earned reinstatement in 1994.

She and her partner, who have been together for 25 years, are planning a private wedding in their hometown Sunday.

“That piece of paper and that psychological effect of being validated by societal standards are very exciting,” Cammermeyer said.

Island County Auditor Sheilah Crider said she doesn’t foresee too long a line when her office opens at 8 a.m., one hour earlier than normal.

Snohomish County Auditor Carolyn Weikel isn’t sure what to expect when her office opens at 9 a.m., which is the regular time.

On a normal day, her staff processes 15 to 20 requests for marriage licenses. With a large demand expected in King County — licenses there will be made available starting at midnight — some residents may drive to Everett instead.

“I don’t think anything would surprise me,” Weikel said. “We’re prepared for a crowd. We just hope it is as a festive and warm environment for all.”

The application fee is $56 in Island County, $64 in Snohomish and King counties, and the acceptable methods of payment vary by county. The license becomes valid 72 hours after the application is filed and is valid for 60 days.

As gay and lesbian couples are signing up for marriage certificates, other Washington adults may be privately celebrating the historic and precedent-setting change in the state’s attitude toward dope.

The decades-long era of marijuana prohibition is ending, as anyone 21 years or older will be able to legally possess and use small amounts of pot.

Unlike the state’s current medical marijuana law, no medical conditions are required.

But here’s the catch: It’s still not legal to buy or grow, at least not for another year.

The delay was created by the two-step legalization process spelled out in the initiative approved by the state’s voters last month.

Parts of the new law go into effect Thursday: decriminalizing adult possession of an ounce or less of marijuana, prohibiting use of marijuana in public settings and setting blood concentration limits for impaired driving from marijuana.

It will be at least another year before adults can go into a store, plunk down about $336 and walk out with a one-ounce baggie of dope.

That’s because the initiative gives the state a year to set up a system of licensing and taxing marijuana producers, distributors and retailers.

The public shouldn’t expect to see a state-licensed store selling marijuana before 2014, according to Sharon Foster, chairwoman of the three-member Liquor Control Board, which oversees the state agency responsible for enforcing the new law.

And that brings us to the “Big If”: If the federal government doesn’t step in to try to block the state-regulated system of selling marijuana from going into effect.

Federal law prohibits the distribution, possession or manufacture of marijuana. Currently the federal government classifies marijuana as a schedule 1 drug, in the same category with cocaine and heroin.

The state’s Liquor Control Board has begun preliminary work on implementing the law and is in contact with state officials in Colorado, which passed a similar marijuana legalization law, said Mikhail Carpenter, an agency spokesman.

Some law enforcement officials said they worry that with just parts of the law going into effect this week, it could create confusion about what’s allowed and what’s not.

“The cart’s ahead of the horse,” said Pat Slack, commander of the Snohomish Regional Drug Task Force. “Why would you give the public an opportunity to possess something that’s a crime to obtain?”

The new law also bans marijuana smoking in public, despite some widely publicized examples in Seattle of people lighting up on election night in celebration of the initiative’s passage.

“It can’t be in public view,” Slack said. “You can’t stand in your own yard and smoke marijuana. You can’t go out on your porch and smoke marijuana. You can’t go out 25 feet from the door of your local bar.”

Violators could face a fine of $103 if they’re over 21 and have less than an ounce of marijuana, Snohomish County Prosecuting Attorney Mark Roe said.

Roe said he wants to talk with local police chiefs, as well as fellow prosecutors from across the state during a meeting this week in Seattle, about what to do with current cases in Snohomish County involving prosecution of small amounts of marijuana.

Of the 17,000 cases handled by his office this year, only 40 pending cases involve possession of small amounts of marijuana, a misdemeanor charge, Roe said.

“For some time, we’ve had diversion program,” Roe said. “They take a class. We don’t charge them with a crime.”

Everett hasn’t updated its ordinances to include a fine for public pot smoking, said Aaron Snell, spokesman for the Everett Police Department. If the department gets a complaint about pot smoking that can be seen by the public, an officer will respond, he said.

Just as officers don’t stop every car they see speeding, “I would be surprised if every time we saw marijuana in public, it would be seized,” Snell said.

Legalizing recreational use of marijuana is a historic move by voters, said Todd Donovan, a professor of political science at Western Washington University.

But until the federal government indicates whether it will challenge the state’s legalization efforts, “it’s still a waiting game,” he said.

Although Washington voters have taken on issues ranging from physician-assisted suicide to various tax measures in the past, “this is kind of out there on its own,” he said.

“It would be up there and maybe have more impact on setting the tone of future policy changes than most things I can think of that voters decided by the ballot,” he said. “This is taking on the federal government and a century of drug policy at the same time.”