This link will get you to the Columbia River page of Oregon Dept Fish and Wildlife. The regs on the Columbia can change at any time during the year and is why I generally don't try to plan anything on it. The way I read it, catch and release is open during non-retention times. Oversize fish can not be removed from the water and must be immediately released, so I'd say go for it. The guide you eventually choose will be able to provide more information for you. You might try http://www.ifish.net
">www.ifish.net (big NW fishing site) for their recommended guide list. They won't list any questionable guides on their site. Many of them will do Sturgeon, Salmon, and Steelhead trips. Good luck on your BDay.