Tom and I made it part way up the canyon until we reached a pour off we could not negotiate. As you go up canyon, it gets steeper, closed in, and the soil changes to volcanic ash with sand mixed in. It makes for very poor footing on slopes. Tom had made it all the way to the maar in the 80’s. That’s over now as the canyon has changed much since then. When I got home, I checked satellite maps and it showed that we were only a quarter mile from the head of the canyon however we could not have gone farther, whatever the case. Although the canyon floor flattens out after the pour off, the canyon walls get very steep, rendering any workaround undoable. We did 5.1 miles with 1614 foot climb. It took us 5 hours to complete the hike.