In the first attached image, I have drawn the pre West Crater lava flow course of the river. I based this on the presence of Tsv rocks in section along the western edge of the flow as well as the thickness of lava over Tsv, paleo Ryegrass Creek remnant, the big kipuka, Augerville...the big flat area bounded by large inflationary structures, the weird pressue plateaus with craters, the fact that landslides most often bound the margin of the river, and other space constraints.
Recall how I always point out that the desecrated mud stack seems to sit too low to mark the flanks of a pre-West Crater valley? Well, I accept it and used an estimate of the basal elevation to build a contour to see what other familiar areas the paleovalley floor could possible relate to...some of these areas include:
The prominent flat surface just below the northern exposure of the Saddle Butte lava...why have I never stepped down on that thing?
The boulder line...the conspicuous line of basalt boulders that may relate to pre-Qbw degradation of the edge of the Qbs flow.