As of 2018, this trail has been renamed Palouse to Cascades State Park Trail. More info here:
I've created an unofficial map of the entire John Wayne Pioneer Trail, not just the well-documented western half. This page is simply meant to be an informative tool for others seeking an overview of the entire route across the state.
Please contact Washington State Parks for up-to-date permit information (much of the trail east of the Columbia requires a permit to access) and trail conditions (including tunnel closures and bridge crossings).
1. Interactive version of the John Wayne Pioneer Trail done with MapMyRun.com.