That old SN track --- which hosted the "SN Detour" trains until the mid-1990s,stretches from McAvoy Road skirting West Pittsburg (now called Bay Point) east under the UP and BNSF tracks to the aforementioned wye ... the classing undercrossing was flooded last I checked, but the tracks are probably still intact. The area where the wye is/was is now owned, I think, by PG&E, and California Coastal Commission might have something to say about that (not sure if that is their jurisdiction or not). City of Pittsburg has spent a lot of money making the old SN right of way through its downtown a nice greenbelt, so I can't imagine they want to see tracks there again. But a McAvoy-to-wye move would be a nice 2 1/2-mile run.