TACOMA, Wash.—As this state rolls out its recreational-marijuana industry this week, it is taking cues from Colorado, the other state where voters approved legal pot in 2012. Now, Washington will provide a second road map for legislators and activists preparing to extend the push to other states.

"We're taking the best of the laws that passed in Colorado and Washington, and tailoring to the circumstances here," said Liz Kaufman, director of New Approach Oregon, a campaign to legalize marijuana.

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