Things to do in Oregon

1. Columbia River Gorge & Mt. St Helens!
2. Japanese Garden. Rose Garden. daytrip to coast. daytrip to waterfalls in the gorge. visit the winerys. drink good local beer.
3. The Portland Rose Garden (International Rose Test Garden) was really beautiful. It doesn't have any real kid-friendly activities, but it is nice to walk around and great place to take pictures. It is in Washington Park which is near downtown.
4. There are some of the best mountain biking / hiking trails in the country just outside of Portland. Beautiful views and a great way to see the mountains and north American rain forest. http://www.scsc.k12.ar.us/2001Outwest/PacificNaturalHistory/Projects/LachowskyR/Default.htm
5. Don’t miss the rose gardens in Portland. They are very beautiful. There are a number of waterfalls in and around Portland and they are all great (like Multnomah, sliver springs etc. if I remember the names right). There are good hiking trails around the waterfalls.
6. Portland is a great city with Mt. Hood nearby, lots of scenic views like the Columbia River gorge. I’d also make the hour plus drive to the coast, Astoria is beautiful, nearby is Ecola State Park and Cannon beach which was voted one of the best beaches in the US. Too cold to swim, but the scenery is breathtaking. It rains often there, but don’t let that stop you!
7. Portland has tons of fun stuff to do. My brother as well as some of my friends from college live there so if you have any questions I can ask for details. If you give me dates, I can probably get info for things happening that week. I know they have lots of free festivals and a very nice waterfront area.
8. Portland has a really awesome OMSI Museum of Science. My nieces and nephew love to go there. It is also lots of fun to walk around downtown Portland(you can take the train for extra adventure) I am not sure how much time you have there, but there is also a cute beachtown about an hour drive away that can be lots of fun.
9. Washington Park - 15 minutes from Downtown, largest public park in the US, home of the Portland Zoo, the International Rose Test Garden, the Japanese Garden, the Arboretum, the Forestry center and the Children's Museum. Plus they're plenty of trails and a cute little train ride between the Zoo and the Rose Garden.
10. The Riverfront/Esplanade, nice trail that circles the Willamette Downtown.
11. Pioneer Square - Portland's Living Room - Harvard Square-like people watching and they always have something happening in the summer weekends.
12. OMSI - Oregon Museum of Science and Industry - right now they have the "Body Art" exhibit with the plasticized bodies.
13. Saturday Market.
14. If they're Catholic - the Grotto, the garden at the top is definitely worth the small donation.
15. Oh, and the Fine Arts Museum is cool too.
16. And maybe not entirely kid friendly (although kids are allowed), but definitely worth a look, there's the Kennedy School, an elementary school that was turned into a pub.
17. Ride the aerial tram from the shores of the Willamette up to the main OHSU campus, it's $4, but the view (on a clear day) are awesome.
18. Multnomah Falls - you can visit just this fall via I-84
19. Scenic Columbia River Highway, access to even more falls as well as Multnomah Falls, and there's the Larch Mountain Lookout. Plenty of easy hiking opportunities as well.
20. Mount Hood, plenty of scenic, picnic and hike opportunities. There's still snow up at Timberline Lodge. However, remind them that Hw 35 is closed south of the I-84 junction (mudslide) so the only access is via US-26.
21. Bonneville Dam, never been, but they say it's cool, supposedly they have these windows where you can see the Salmon swim.
22. A LOT of hiking opportunities all the way up to Hood River, specially around Eagle Creek.
23. Hood River, home of all wind water sports.
24. There are plenty of Wineries that offer tours as well as wine-tasting. Not exactly "kid-friendly", but it's educational, yeah that's it! :-)
25. There's also a bunch of places that let you pick your own berries. Apparently this is fun for the "Gringos" :-)
26. A lot of towns have Farmer's Markets at this time.
27. Mt St Helens National Volcanic Monument. The drive there is long but quite beautiful once you get past the "red-necky" areas. Plus there's plenty of educational and hiking activities. My favorite was the Ape Caves, a defunct lava tube that you can hike through and Cold Water lake that totally lives up to its name. :-)
28. The Coast - the best thing is to drive from Astoria all the way to Lincoln City, but it's a haul so I'll split it up.
29. Astoria, home of plenty 80/90's movies, "The Goonies", "Short Circuit", "Kindergarten Cop". Very quaint little town, but it's packed on the weekends. The best thing is the almost 4 mile long Astoria Bridge that crosses the Columbia. You can drive there via 26W to 101N or you can drive there via US 30 which sort of follows the Columbia.
30. Seaside, typical tourist coastal town, they have an aquarium and boardwalk.
31. Cannon Beach / Ecola State Park, beautiful coast, less touristy than Seaside, but still crowded. Home of the Haystack Rock.
32. 101 between Cannon Beach and Manzanita, probably some of the best views of the coast and coastal cliffs. Manzanita is a cools town to stop at. Past Manzanita, 101 curves inland and is less scenic, but still nice.
33. Tillamook, there's the Tillamook Cheese factory - great Ice Cream. Here's also the beginning (or end) of the Three Capes Scenic Drive. Starting with Cape Meares, a lighthouse perched on top of a 400 foot cliff! Cape Lookout, it's a nice day-use area, but there's also a spit of land that juts 2 miles out into the ocean. It's a really nice, really easy hike to the tip and you are rewarded with beautiful views (so I'm told - the time I went it was shrouded in fog) and even whales when the time is right. After that there's Cape Kiwandas, a cure little coastal town.
34. Lincoln City - Home of the Chinook Winds Casino and plenty of Outlet Malls.
35. Newport Oregon, beautiful coastal city. Home of the Oregon Coast Aquarium where Keiko (Willey from "Free Willey") was housed until he was returned to "wild". The tank where he was kept has been turned into one of those tanks you can walk through. It's actually quite decent. Although it's a haul.
36. Crater Lake - You have to see it to believe it. :-)
37. First option from Portland is do the scenic Columbia River Gorge Highway ( 30min from the city). You can see a lot of scenic sites & waterfalls. The drive can take you up to Hood river and back. Look at http://www.columbiariverhighway.com/ (The map in the web site is useful)
38. Route 101 on the Oregon coastline all the way down to the Redwood National Forest in the northern tip of California. You will have to stay overnight on the way to complete the drive but the view is worth it. Suggested place to stay on route 101 is the Overleaf lodge on Yachats/ Tu Tu Tun lodge at Gold Beach or Requa Inn in Klamath ( CA). If you are not doing the coastline you could also do the wine country around Portland or may be take a longer drive to ( 7 hrs ) to Crater Lake National Park.