If you want to grow tomatoes make sure your property has room in a sunny spot for a greenhouse.
And check the soil conditions if you plan to grow outdoors.
I hope someone from south sound can chime in.

And, remember there is a deer problem, so plan on fencing.
You'll have fun gardening in the PNW. Things grow so well.

The things that grew well for me last year,inside a greenhouse were bush beans,squash,peppers,salsify,cucumbers and tomatoes to a certain extent.They could have been better,probably needed more compost.
Outside, strawberries,blueberries,mulberries,honeyberries-the Japanese type Haskap,Cornelian Cherry, and again bush beans.I put in blackberries last year and they grew well and should fruit this year.Had some fruit on a combo Apricot(Puget Gold) and Plum with Shiro fruiting.Three other plums on it may fruit this year.The tree is still young.My Jostaberry is fruiting more every year.
About the only things that didn't fruit very well were melons,in or outside a greenhouse,although some people may get the small type to mature,we usually don't get enough heat.That can happen with tomatoes too. Brady

Microclimates can be created. I would consider good drainage in places that get a lot of rain. Olympia does get warmer in the summer and colder in the winter. It is always interesting to see the warm/cold temps around Potlatch.
Closer to the water also means more moderate temps, but not good for tomatoes or melons. Overall a much more garden friendly area than Oklahoma. I would also scope out community gardens where looking for property.

Thanks so much for the responses! It's good to hear lots of positive comments about gardening in the PNW. I'm sure you're all correct that it's harder to garden in Oklahoma. Around here, you're better off planting your tomatoes in partial shade to save them from the sun and finding some way to provide a windbreak to save them from the hot dry winds.

It sounds like we should plan on a greenhouse for the tomatoes, make sure we have drainage for probably everything else, and be prepared to spend money on deer fencing.

As far as being more moderate close to the water, I gather it might extend the growing season but not provide the warmth required for some crops? And how far is " close to the water"?

Thanks again!

I think everyone else already said it; the number one thing is make sure you have place with good direct sunlight from the south. If you can get it next to a south-facing wall or other heat-sink so much the better.

Where I live in Seattle you don't have to have a greenhouse to grow tomatoes, but you will probably want to cover them in a hoop house or something until July probably. If you don't, you can still get fruit, but it will be in September. Be sure to choose appropriate varieties, in generally anything the seed catalogs claim will riper in 75 days or less is probably a good bet, and Russian heirloom varieties have always done well for me. I once tried to grow Hillbilly tomatoes here; this was a wonderful variety, but I only got a few fruit very late in the season.

I suppose a greenhouse would be great if you have the money to spare on it, of course. Seattle is right on the Puget Sound, so cold weather is mitigated, but we have to deal with cool springs and rainy and early summers.

Things that grow very well include brassicas (esp. kale and Asian greens such as mizuna), leeks, pole and bush beans, peas, lettuce, strawberries, etc. Cucumbers grow too in the open here too, but they are challenging. I have never had good luck with bell peppers at all, but I know some people who have grown them in a good micro-climate. I have had good luck with winter squash in the past, but one year they were very disappointing, and made practically no female blooms. That year was especially cool.

In short, chose your crops and varieties more carefully here, and don't try to grow warm-weather crops without a good sunny area!