Good places to park are RiverPlace Marina (end of S.W. Montgomery St. off S.W. Front Ave.) or the Portland Boathouse (S.E. Clay St. at Water Ave.).
You could walk or bike the 3-mile Willamette River loop between Portland's Hawthorne and Steel Bridges in less than an hour, but it's worth a full day, with stops to eat and shop, on-the-water excursions, and a detour to a children's science museum.
If it's sunny, you'll have plenty of company ― especially this month, with Portland Rose Festival carnival rides filling the west bank's Gov. Tom McCall Waterfront Park (Jun 1-11; 503/227-2681) and dragon boat racing (Jun 10-11) in the river off RiverPlace Marina.
What: Oregon Museum of Science and Industry, nice and cool on a hot day, with plenty of brain-stretching entertainment for the younger set. When: Tue-Sun through Jun 18, daily from Jun 19. How much: $9, $7 ages 3-13, ages 2 and under free. Where: 1945 S.E. Water Ave.; 503/797-4000.
Alder Creek Kayak & Canoe
What: The store offers a guided sea kayak tour from the boat launch near its shop at the Portland Boathouse (under renovation; look for the mobile unit in the parking lot) upstream to Ross Island. How much: $40. Where: 49 S.E. Clay St.; 503/285-1819.
Portland River Company
What: Guided paddle trips to Ross Island from RiverPlace Marina. How much: From $43. Where: 0315 S.W. Montgomery St.; , 888/238-2059,503/229-0551.