I've seen the Escure Ranch mentioned in the paper a few times, and each time I read about it I think I need to look into it. 30 miles of non-motorized trails, an historic ranch, wildflowers, Towell Falls. Sounds interesting.
I finally searched and found the above map (pdf file here) - and it turns out I've already been there, or along the edge of it. Surprise! Escure Ranch is within the Rock Creek Recreation Area (BLM land) and the Columbia Plateau Trail follows along the western edge, while the John Wayne Pioneer Trail skirts the northern edge.
I remember seeing a trail off the CPT last year in this area and thought of taking it, partly to relieve the dead-straight monotony of sections of the CPT, but I was on a mission to see how far I could go in a day on the trail. This looks like an area that needs further exploration. I'll have to look into the camping options. I want to ride whole Columbia Plateau Trail this year, but the Escure Ranch area could be another long weekend bike trip.