The Columbia River draws the line between Washington on the north, and Oregon on the south, for 309 miles.  But at Portland, the river turns north, before bending west again to empty into the Pacific Ocean.  That means that Google will keep telling you to travel I-5 north from Portland, OR, into Washington to get to Astoria, OR.  And Google will navigate you through the confusion of Longview, WA streets to get you back across the Columbia to join US 30 in Oregon, as it goes west to its end.  It's a pleasant drive through farmland and forest, picturesque old (and some dilapidated) structures beside new buildings (eg quaint Clatskanie, OR), and the road is almost all smooth.  (US 30 travels from Atlantic City to Astoria . . . more interesting info at https://en.wikipedia.org/wiki/U.S._Route_30 )
 
Astoria and the Maritime Museum
Astoria is only about a 2 hour drive from Portland, so it's a great weekend mini-vacation, but you may want to take a longer adventure from there.
 
I was afraid I had passed the Columbia River Maritime Museum, but big bold letters on the roof soothed my worries.  I was excited to see several huge ships on the Columbia, and anxious to take pictures . . .
 
The Maritime Museum houses exhibits on ships/boats, weather, historic Astoria & exploration of the coast of the Pacific, Native Americans, fishing, whaling, the largest fish cannery commerce (Astoria), WWII . . . Plan for a couple hours.  $14 adult admission, passes available (including a reciprocal that gets you into other interesting places).  Two gift shops dazzle both kids and adults.  The museum has several interesting hands-on activities for kids, as well.  Across the street/highway from the Maritime Museum is an aquatic center (swim), and a cinema.  Plenty of restaurants to get interesting food of different, and familiar, kinds.
 
The trolley at Astoria has one accessible stop--so a wheelchair can only get on and off at one place ($1 per ride, or $2 all day; see https://www.travelastoria.com/trip-ideas/ride-the-historic-trolley.html  ).
​There's a nicely paved walk along the river, but it was too hot a day for my legs to enjoy--evenings or overcast days would suit me better.  Notice a signed reminder that you are in a tsunami-potential area. Pay attention where to go.

More about Astoria, Fort Clatsop, and Fort Stevens
https://www.travelpacificnw.com/accessible-travel-blog/coffenbury-lake-astoria-2
 
Fort Stevens State Park Campground
We stayed at Fort Stevens State Park Campground just down the road past or in Warrenton (great views of the water; people sell firewood along the way, $8-10 a bundle, but the park has it for $7 a bundle).
 
Walmart and Costco, eateries, and a laundromat are close.
https://www.walmart.com/store/5861/warrenton-or
https://www.costco.com/warehouse-locations/warrenton-or-1059.html
 
Fort Stevens is a very popular place for cyclists (every age, and the whole family), and for pet walkers, joggers, and so forth. Reservations go fast, even on the first day you can reserve for several months ahead!
https://oregonstateparks.org/index.cfm?do=parkPage.dsp_parkPage&parkId=129
 
Fort Stevens Campground has:

• 150 full hookup sites with electricity and water
• 302 electrical sites with water
• 15 yurts (7 pet friendly)
• 11 deluxe cabins (5 pet friendly)
• paved parking/picnic table/fire ring at all sites
• flush toilets and hot showers
• RV dump station  
• 9 miles of paved bike/wheelchair paths
• 10 miles of hiking trails, trailhead for the Oregon Coast trail
• freshwater lakes and day use areas (campground pass also allows access to day use areas)
• two reservable covered picnic shelters
• historic military sites/museum a short drive from the campground

 
Shipwreck and Sunset Beach
A 1906 ship wreck is accessible from the campground via paved trail, but if you are in a wheelchair, you need a way to get from the end of the pavement onto the beach.
 
South of the shipwreck you can drive on Sunset Beach, a long sandy shoreline without rocks and debris, so great for playing in the water, the sand, flying kites and all those popular seashore activities (well, maybe not tidepools).  It was a perfect day (25 July 2019) to spend at the beach:  70 degrees, sunny, nice breeze to keep it from getting too hot (but wear sun protection, and late afternoon a jacket).  Access the beach by vehicle further south than at the shipwreck, which has nearly wrecked quite a few vehicles.  Our party had to tow a vehicle out of the loose, deep sand.
 
Staying in a yurt
Others tented, I had a yurt.  It would sleep 5, but you can have as many as 8 at a site (extra tent).  An extra vehicle costs $7.  Yurt sites 6, 12, 13, 18, 19, and 20 are best for the disabled (flat).  You will need a helper to open the windows of the yurt, as it gets too warm in the summer afternoon.  They do have heaters for less warm months, also electric lights, and an outlet. 
 
The yurt has a bunk (twin top, full bottom), and a futon bed that makes into a full.  It sleeps 5 if you have 2 pairs that can share a bed. Not so many if everyone needs a separate bed. We rigged a privacy curtain using a long cord and 3 light blankets, with snack bag clips/clothes pins to attach the blankets to the cord. The mattresses are hard, so if that is an issue for you, you should bring a foam pad to soften your sleep.
 
The restrooms/showers are about a block away, easy paved wheeling.  They are kept clean (be sure to thank the volunteers), though one day someone put paper towels in the toilet--either from rudeness or ignorance:  people from other countries may not be familiar with our facilities.  There's a handicapped stall in the main restroom, and a separate handicapped restroom, in the facilities near the yurts.  I only had to wait for a shower once (over 20 min) when a mom and child were using the handicapped shower.  Plenty of hot water, in fact one person thought it too hot.
 
Kayak tours, Fort Clatsop, Historic Military sites
There are plenty of activities to keep one entertained for a week.  I list only a few:
 
When I called ahead, they did all they could to dissuade me from the kayak tours.  Perhaps they had a previous problem:  the woman kept stressing that I would be far from medical attention for a half a day.  No problem for me.  But then she insisted the point of embarkation was inaccessible.  I got a helper to take me to look it over--I think they could have accommodated me if they had been willing, and I would have had a helper.  But without trying it, it might be less possible than it looked.   Fort Stevens State Park hosts inexpensive kayak tours (click on link above), and so does Fort Clatsop.
https://www.nps.gov/lewi/planyourvisit/paddle-tours.htm
 
I wish I'd had half a day to spend at Fort Clatsop--rebuilt from drawings of the explorers Lewis and Clark, who stayed there winter of 1805-6.  Rangers in costume answer questions, give interesting talks; there's a junior ranger program, museum/gift shop, and outdoor exhibits.  The paths were nice and wide, and barked.  No problem in dry weather . . . usually barked paths are ok for less than dry weather, too.
 
On my way home I swung by the historic military sites at Fort Stevens Military Reservation (Civil War through WWII).  I didn't have a helper to load me, so I just saw what I could from the car--which was quite a lot:  the old cannons, lots of old foundations that leave you to imagine how they lived in such small quarters, several cement structures still standing, and the battlements (lots of stairs, but I could at least see them) . . . there were plenty of paved paths, and the museum I would have enjoyed.
 
I determined to go home north via the Astoria-Megler Bridge, check out Long Beach, WA, and drive home on the Washington side of the Columbia River.  The view from the Bridge is spectacular! 
 
I'm excited to travel by way of Astoria again, Astoria has a lot more to offer.  I also want to see the two lighthouses on the Washington side, picnic at a great scenic overlook there, and explore Long Beach, WA.

Want to wander through the woods, spend some natural time among the tall trees and lush undergrowth of the Pacific Northwest?  Enjoy campfire cooking and camaraderie?  Iron Creek Campground and picnic area offers all that.  Iron Creek runs through the forest at the northeast foot of Mt. St. Helens.  Its waters are fed from the snows of the mountain.

From Portland, travel north on I-5 a little over an hour to exit 68, then turn east on Hwy 12 toward Randle, WA. You'll pass over the tip of Mayfield Lake, drive by the north end of Rifle Lake--and there's an overlook there for picture taking.  Continue through the small town of Morton, and pass/stop by a Salmon hatchery and a trout hatchery along the way.  Google says it takes about an hour (45 mph), but on the way back we made it in 50 min., when the car was tired and wanted to get home.
 
Near Randle you take National Forest road 25 south to Iron Creek Campground--the picnic area is just past it-- (there's a Ranger Station in Randle for Gifford Pinchot  National Forest, if the road names get confusing--Monday through Friday 8am to 4:30pm, except lunchtime).  The campground and picnic area are connected by short trails.
 
The Campground has 98 sites--single site fee $20, extra vehicle $10, multi-site fee $38--firewood $7/bundle . . . there are friendly camp hosts to answer questions.

You can make reservations at Recreation.gov (non-refundable fee).  The District office is in Vancouver, WA--see https://www.fs.usda.gov/detail/giffordpinchot/about-forest/offices
 
We visited June 9, 2019.  Don't let the mileage fool you, the 10 miles to Randle takes half an hour, and the 54 miles to Cougar are similar--the road is not exactly smooth or built for speed.  You are not in the fast lane now.  Just enjoy the scenery (Driver watch the road!).  Not a lot of traffic when we went, but enough.
 
Loops B, C, and D have accessible vault toilets (all toilets are vaults)--restrooms are kept clean.  If you feel uncomfortable on the small surface, you could bring a commode and set it over or next to the toilet each time you are using the restroom.  Dispose of waste appropriately--if you don't know what's appropriate, ask the hosts.
 
Just beyond the campground is the day use picnic area.  It has a covered group area and 2-3 single tables.  Short barked trails connect the picnic area and the campground, and there are some other scenic trails.  Weather has downed some trees, which then must be cut to open the path.  Not all were cut when we came to them.
 
A bit later in the year you can continue on FS 25, and make a loop around the east side of Mt. St. Helens--there are a few options . . .

1.  loop around the south side of Mt. St. Helens and see the Ape Caves (not in a wheelchair, but nearby is a boardwalk through the forest--very pretty, but you might need a helper for safety and slopes), and stop for a picnic and dip in the lake at Yale Park (accessible paved path down to the lake--weekdays free),
2. You could head over toward Mt. Adams (get directions--not all paved) and lower falls to Cougar by Yale Lake, or Carson on the Columbia, through Stevenson, over Bridge of the Gods, to Cascade Locks and/or Bonnevile Dam and Multnomah Falls---if you have lots of time to enjoy it all . . . 

A neat video from the other direction gives more info:
https://www.fs.usda.gov/recarea/giffordpinchot/recarea/?recid=31306
 
This map gives a general outline of roads and amenities from Mt. Rainier, WA in the north to Multnomah Falls, OR--including Mt. St. Helens and Mt Adams.  Next volcano south of the Columbia River is Mt. Hood--lots of attractions associated with that!

  In this article look for
-Maryhill Museum of Art 
-The Car Show of 10-5-19 (annual event)
-Stonehenge, War Memorials, Goldendale Observatory
-Washington & Oregon State Parks in the area
​-From Portland you can travel I-84 or Hwy 14,  6 bridges
-Eats & Sleeps within 15 miles (Biggs Junction, Goldendale)

Note:  lots more photos and info at 

• https://www.travelpacificnw.com/accessible-travel-blog/columbia-hills-maryhill-2

Maryhill Museum of Art holds so much more than art!  It is also a museum of Native Americans, the railroad, royalty, fashion, history:  just about something for everyone.  We chose to go this time on the date of the annual car show (10-5-19).  Although my grandson and I are interested in both the museum and the car show, I can imagine a family might find it a good opportunity for each member to explore different interests.
 
Accessibility
Entrance to the museum includes a pretty long, steep incline, and after wheeling around the grounds at the car show, I had to have my grandson push me up it.  Built as a mansion, some of the rooms are intimate displays the staff has so cleverly arranged. The 4 levels of the museum are served by 2 accessible elevators.  I had no trouble wheeling around, and another woman delighted to tell me that they have wheelchairs to lend on site.  I forgot to check the restrooms, but when I called, they said the restrooms are accessible.  I obtained a free 1-page map and visitor guide at the front desk, for reconnaissance.  For those “disabled” by hunger, a small café is located in the museum.
 
The Grounds
On the grounds are large grassy areas, parking (accessible as well), sidewalks easy to wheel, expansive views of the Columbia River all the way to Mt. Hood, tables for picnicking, interesting outdoor art, and room to let the kids roam & run.  The grass is a bit rough terrain for a self-powered manual wheelchair, but not impossible.  On the day of the car show it’s full of cars on show, though there’s still plenty of room for the foregoing activities, as well.  PS--note the wind turbines on the bluffs above.
 
The Website
The Website for the Museum is a fantastic creation in itself, well worth some time exploring.  Five stars for beauty, ease, and inclusiveness.  Beside the usual admission information with map & directions, you’ll find a calendar, information about exhibits and events (indoors and out), nearby attractions and activities of all kinds (including some places to stay), a blog with all kinds of articles of interest.    https://www.maryhillmuseum.org/
 
The Car Show
The “Car is King” show we attended on the grounds of the Museum is an annual 2-day vintage car show, race, and hill climb.  For classic car lovers it’s a must.  There are food and other vendors, and porta-potties, even for wheelchairs.  The grassy grounds are not smooth.  Here’s the 2019 schedule https://www.goldendalechamber.org/event/car-is-king/
​

Lan Su Chinese Gardens--photos above
Lan Su posts a calendar of its offerings by the day and the month on its website, so you can choose to go for a major event (such as Chinese New Year, the Autumn Moon Festival, or the Ninth Moon Floral Design Showcase:  Mums’ favorite), or on a day when there are fewer folks, but still activities and demonstrations in which you would like to take part.  Either way, go when you can spend the day without being rushed.  Or get a membership and come often to soothe your soul and senses. 
See https://lansugarden.org/things-to-do/event-calendar/
For more photos, scroll down at "Celebrating Chinese Style"

• ​https://www.travelpacificnw.com/accessible-travel-blog/celebrating-chinese-style

​
Some of the everyday opportunities to enjoy at Lan Su

• Tours (great cultural background information) 
• Seasonal Plant Guides; to download:  https://lansugarden.org/things-to-do/ongoing-programs/
• Family Discovery Guides (like a scavenger hunt) Download at the link above
• Changing Art Exhibits
• Calligraphy & Brush painting demonstrations
• Music or Poetry in the Teahouse
• Tai Chi instruction
• Kung Fu classes on Tuesdays
• Chinese Conversation
• Poetry workshops & practice
• Learn to play traditional Wei Chi (Go)
• Lectures on Chinese Medicine

 
The garden has such a variety, that something is always in bloom.  My photos are from September; there are lots of videos of the garden out there--such as at 

• https://www.youtube.com/results?search_query=lan+su+chinese+garden+portland

But no matter how many photos and videos, as well as a virtual tour on the garden’s website, nothing is the same as being there.
 
Accessibility
You can see all the garden views from a wheelchair.  There are barriers to enter only a couple of spaces (you can still get good views).  On a day they are staging performances, you will want to arrange to be where you can see before the performers get in place.  You may not want to be in the same area as the audio.  They have a men’s restroom, a women’s restroom, and a family type restroom—all pleasant and accessible.
 
Teahouse & Gift Shop
The Teahouse offers a selection of teas to enjoy there, or buy and take home, a few items to eat, and both indoor and outdoor tables. It’s very pleasant to be there when there’s a live musician playing a Chinese stringed instrument.  Bring a little cash to tip the artists.  The brush artist told me he gives all his tips to the support of the garden.
 
The Gift Shop is small, but is a splendor of wonderful things.  When I was there, the Hall of Brocade Clouds also had artwork for purchase.  The gifts you give give back to the Garden, and the greater community.