If you were wanting to be north of Burnside at the end of all this, when you get to Lewis and Clark Circle, (or whatever it is), carefully go the wrong way down the 1-way for a teeny bit, and hop onto Stearns Way, a former street that switchbacks down to Burnside. You cross at NW 24th, and you are in NW Portland...
Note: descending Park and or Salmon through the west side of downtown is.... interesting. The road is steep, and not in the best of condition. Once you get to Lincoln HS the grade eases and it is a more-relaxing ride.
Returning to the west side - the best way I've found is to follow SW Jefferson until it makes the big bend left (past the Vista Bridge) - hop onto the path on the right. Switchback up. Take a left turn on the path when it is offered. It puts you at the entrance to Washington Park.
Alternative routes are climbing Vista or Montgomery (pretty, but steep).