On an impromptu trip up the BNSF maintenance yard, which runs under the Branner Trafficway viaduct, I managed to get shots of the largest number of locomotives I've seen at once, much less of the same model.
This group of roughly 25 to 30 B23-7s, a majority of which still retain their ATSF livery, sits on two separate lines inside the yard, dead, waiting for whatever it is they're here for. I'm not gonna guess a new paint job, though most looked very clean.
Another angle can be seen here
Canon EOS 30D
Sigma 70-300mm telezoom
ISO 400 @ 1/160 f/6.3