So I found a Guerrilla Painter 9x12 pochade box on clearance, which meant I had to take it for a test drive this weekend! I went to Locke, CA, with the Sacramento Plein Air Painters meetup group. Locke is a turn of the century old-west town south of Sacramento, now owned by the CA State Parks department.
This is 3 hours of work on location - I might work on this painting some more the next time I go to Locke, as I can't use my usual technique of layering during a single session of plein air. This is painted on a 12x12" sheet of gessoed Dibond aluminum.