I located the juvenile Sabine's gull at around 6:30 pm today (9/7) and signed up for the listserv just to post about it!

The gull was in the water among a bunch of mallards. I originally noticed it within the duck flock because it was feeding like a phalarope would. There were a few other birders present and we all got good looks at it, and it stayed in the western pond the entire time we observed it.