The Possibilities are Endless, these are some places to check out!
Rock Creek Camp
4th July Camp
Siouxon Creek Trail
As an alternative to the High Pass Challenge, I created this route from the book “The best bike rides in the Pacific Northwest”
Map connector trails and routes to begin either in Tacoma or at least Federal Way area
use Cedar River Trail?
Here are a couple potentials
Made a couple routes based on some folks who have done this already.. Looks like there are of course some great options. Here are a couple routes
Rainier to Woodland
Tacoma to Gresham