This is steep climb from the Orange Trail
(ravine trail in lower preserve). You can cut straight through to get to Old Oregon Road Trail, or do the whole Yellow Loop.
This trail connects the lower preserve to the upper preserve. There are some steep sections to it. If you explore a bit north of the Yellow Trail
near Old Oregon Road you can find the ruins of the Meyer Mansion. Not much is left - just bricks, a bit of foundation, and the outline of an old grass tennis court (now part of the woods). There is a root cellar as well.