In the current issue Birder’s World, I have a site guide for Mount Tabor Park in southeast Portland. Mount Tabor is a forested hill (actually an extinct volcano) surrounded by residential neighborhoods. The elevation and vegetation attract good numbers of migrant songbirds every spring. A similar effect can be seen at Pittock Mansion in northwest Portland.
Here is the view from Pittock Mansion, with snow-covered Mount Hood in the distance. The forested hill in the center of the photo is Mt. Tabor. You can see how these islands of habitat rising above the urban sea would be attractive to migrants.