Yes, but it may not be for everyone. Could be lot better. Here is a start at some maps of routes.
Easy grades and fairly quiet streets are possible if you go all the way to the International District and double back on 12th S. Thanks to Stu Hennessey for this West Seattle Spokespeople ride route.
A quicker but steeper connection to Mountain to Sound Greenway and Beacon Ave is via busway trail and Holgate, but it’s better westbound. Eastbound involves poor access to a stair carry and sidewalk to get up the Holgate viaduct over I-5.
Via Georgetown is possible a few ways: 1st Ave S Bridge from West Duwamish Trail, or 1st Ave S viaduct from Spokane St Bridge.
There is also the newly re-opened South Park Bridge, via the West Duwamish Trail and route through South Park, but not sure about bike friendly routes on east side. Anybody familiar?
And you can continue south from South Park on busy 14th Ave S, then along a really crappy little trail/mudpatch by the Machinists union to West Margi
nal Place to get to a little ped/bike bridge over the Duwamish at Cecil Moses Park and the East Wind Fish Weir site, and then south on the Green River Trail at S 112th St.
http://www.gmap-pedometer.com/?r=6475498
http://www.gmap-pedometer.com/?r=6475820
http://www.gmap-pedometer.com/?r=6475817