First thanks for all the info that made my recent trip to Mt.CO.& WY.a sucess I am now planing a trip to Portland via rail
to visit relatives I will have 3 pre teens in tow.
Instead of flying back home via portland I
am considering renting a car one way to say maybe sacramento and exploring the oregon coast.
I would welcome any ideas

At a minimum, in Oregon, stay at Cannon Beach one night, visit the Sea Lion Caves, check out the dunes. In California, vist the grand Red Woods and drive down the coast, perhaps staying for one night in Mendocino.

I would second the Cannon Beach thought. Newport and Florence both have great beaches and wharf areas to shop and explore. Sea Lion Caves is neat for the kids although there are quite a few spots along the coast where you can see them for free. The drive between Florence and Newport is one of the best in the country IMO. Farther south Cape Arago HWY. is the best undiscovered gem on the coast. Bandon south of Coos Bay would be a good place to see that from.
Depending on the time of year you could do a whale watching excursion from several places...the best Ive been on are out of Newport. Newport also has the Oregon Coast aquarium which would be a good stop for the kids.
Rogue River Jetboat excursions run up and down the Rogue River out of Gold Beach. The trip up the river is quite scenic.
If you are adventurous you could rent
an ATV and ride throught the dunes.
As a long time resident of the coast and now the Rogue Valley I will say you wont regret your trip...12 years ago I made one myself...now I live here!

Thanks,Im taking notes.
The jet boat sounds great,
Im also looking into a whale watching trip also

Portland has quite a bit to offer. I highly recommend OMSI for kids (and adults). I can spend a full day there easily. It has a great IMAX screen - much bigger than many others I have seen (I was very disappointed to learn they weren't all that size!).

The Oregon coast is gorgeous. I think the Oregon Aquarium is very nice and well worth it. Newport is a nice town (my favorite). Walk on the docks and check out the fishing boats. In town there is a dock full of sea lions barking and fighting for free. I have never been to the sea lion caves, not sure it is worth paying for. The best scenery on the coast will be from Cannon Beach to Florence. After that Hwy 101 goes inland to Bandon. Check out the cheese factory in Tillamok and Bandon. Bandon has a tasting area with all different types of cheeses.

I love the Rogue Jet Boats. I have taken the long tour twice and loved it. If at all possible take the long tour, the ride is much more exciting where the others turn around. They all see beautiful scenery. Maybe read a short Zane Gray book on the train to the kids - you'll see the ruins of one of his houses. Might help pass the time on the train.

I think you can also take a dune tour that the kids might enjoy in Florence.

As you get further along in planning and have more specific questions let us know!

Enjoy!!