got a street map of seattle laid out or up on google maps?
more common would be to roll up to the pike place market on western to blanchard, or detour for a croissant and a cuppa coffee at the Market, then 1st/pike to 4th to blanchard.
..... Blanchard to 7th turns into dexter which rolls all the way to the fremont bridge without the longish route ascribed above.
turn right at end of bridge, look for pickup of B-G trail at first stoplight 34th/stone way.
heading to eastlake from blanchard is even more direct to magnuson park via the university drawbridge. go to blanchard via above, but all the way to westlake. left on westlake to lake union, then right to connect with eastlake. follow eastlake along lake union until you reach the university drawbridge, exit first ramp extreme right after bridge 270 degrees and pickup BG trail directly underneath the drawbridge. much new trolley tracks on this route, be aware if choosing westlake to eastlake route.