An aerial view of Mocks Bottom barracks and the area near N Willamette Boulevard, N Killingsworth Street and N Greeley Avenue, circa 1945. Notice the building at the northeast corner of N Greeley Avenue and N Killingsworth Street – it was designed to accommodate the curve needed for the streetcar route. This route was no longer in use by the time this photo was taken, and the Bess Kaiser Hospital had not yet been built.
Aerial of Mocks Bottom Barrack, circa 1945: A2005-005.1416.9
Vintage Portland 
On 21 April 1919, the Victory Loan Flying Circus flew an air show from this site extending beyond the lower left corner of this photo. Wooden ramps were constructed to bring the airplanes down from the train cars parked on the track. In those days, there was a flooded space just below the tracks. Don Nelson published an excellent photo showing the airplanes parked in the field along the west edge of the flooded area. Alan Toelle
Mio Sushi and some other businesses now occupy that building with the rounded shape. Neat Union Pacific steam locomotive, too which looks like it may be a 4-8-2 ‘Mountain’ type.
Not much traffic back then.
There are several of those curved buildings around town, built to accommodate streetcar routes. Another that comes to find is at the intersection of SE Bybee and Milwaukie. I think it’s a ZoomCare these days, but it was a bridal shop for a time and before that, a Rexall drug store.