I-84 comes in from Idaho at Ontario and heads northwest to the Columbia River and follows the Columbia gorge to Portland. It roughly parallels the Oregon Trail
US-26 comes into Oregon with I-84, US-20 and US-30 at Ontario and then leaves them to head west/northwest across the state to Portland and then on to US-101 south of Seaside and north to Astoria.
US-30 comes into Oregon with I-84, US-20 and US-26 at Ontario and then leaves them to head west/northwest across the state to Portland and then foolows the Columbia River north and west to US-101 at Astoria.