Land in Portland and admire the famous new PDX airport carpet before hailing a taxi. The 5-mile drive to the McMenamins Kennedy School is quick, and there will be endless entertainment for the whole family once you get there in this former school-turned-hotel. Take the kids for a snack in the restaurant and exploring the halls before heading out into the city.
Start by taking a TriMet bus to the Oregon Museum of Science and Industry (admission $13.50 adult, $9.50 child). OMSI offers an array of exhibits friendly to kids and adults, and is located on the eastside esplanade overlooking the river, with a view of downtown. Spend a few hours experiencing the museum, and then burn off some energy walking along the southern end of the esplanade where you'll get a ground-level view of the city.
Then it's contrast time - the MAX line will get you across the beautiful new pedestrian, bike and public transit bridge and from there you can buy a ticket to the Portland Aerial Tram. For $4.50 each (round trip, and kids under 6 free), your family can experience the most dramatic view of the Portland area available. The tram makes its way from the South Waterfront to the Oregon Health Sciences University campus atop the West Hills, with downtown and the river laid out below, and the eastside and mountains beyond in the background.
Back on the ground, it's time to head outside. If you're feeling adventurous, rent a car for the afternoon and head out to Sauvie Island for berry picking and a couple hours on the beach, or pumpkin patch and corn maze exploring, depending on the season.
If you'd like to avoid the car, the MAX will get you to the Portland Zoo and the Hoyt Arboretum, where exotic animals, plants and walking trails can fill an afternoon. Stop in at one of the many downtown food cart pods on your way for a variety of street food lunch offerings that will please everyone.
When tiredness starts to set in, ride the MAX back down into the city and transfer to a trimet bus that will take you back to your hotel.
The Kennedy School is the place to be at night. Settle into the movie theater couches and order pizza and a couple of beers delivered right to your seat while you watch the show. Take the kids for a late-night dunk in the outdoor soaking pool, which is big enough to splash in and just warm enough to be luxuriously relaxing. Then head to your uniquely decorated room and fall into bed.