Could it be the Aurora Avenue Bridge ? @witchlockmonsterfox
I thought the picture was taken after August 1974 and that was actually correct! The picture was taken in front of the Aurora Bridge. A Visual Timeline did a little more digging and found the following information about the picture :
“It appears this photo was taken on Sept 1, 1974, morning. The photo may have been taken by Mary Chino, Liz’s best friend who owned a houseboat right there on Lake Union. By mid morning, Ted was shopping in Portland, Oregon. By mid-afternoon, he had picked up the un-named hitchhiker at Boise.”
From The Phantom Prince :
“Mary [Chino] cooked a going-away breakfast for Ted on her houseboat. It was Labor Day weekend, still sunny and hot, and Ted took a last look at the lake and the matching blue sky above it. He would miss Seattle, he said, but he was glad to be starting fresh in Utah and convinced that he would finally be able to concentrate on getting his law degree. He tickled Tina one last time, gave Mary a hug, and then turned to me. We held each other for a long time, then kissed goodbye. Ted waved and honked as he drove off, his Boston fern beside him in the front seat."