One of my favorite routes is the I-5 bridge / I-205 bridge loop. During the new condo construction near Wintler park things were a mess; I actually got chased by a security guard when I rode through there a couple of winters ago. Since they finished the condos though it is quite nice through there.
The MUP that starts off Columbia Way at the park (@ Marine Park Way, but there are several access points east of there along Columbia Way) goes out to the river then follows the riverfront east all the way to Wintler Park. There is a new part of that path that goes behind the 3 new condo buildings and directly into Wintler Park without ever getting on Beach Drive (the path is seen here on the Google satellite view - http://goo.gl/maps/pWnt
From Wintler Park going east I used to backtrack along Beach Dr up the hill to Riverside Drive, then one day I saw a guy going into Wintler Park on a bike as I was going back out Beach Dr, then I caught up to him later up on Riverside Dr. I asked him how he got ahead of me and he told me about a shortcut through the east end of Wintler Park. If you follow the path east past the restrooms in Wintler Park there is a dirt path to the left just as the paved path starts to loop down toward the river. Follow that about 100' to a short stairway and you emerge at the bottom of Chelsea Ave just below the RR crossing. Ride directly up Chelsea Ave, across Riverside Dr, and on up to Evergreen Hwy.
Hope that helps.