On the clear morning of 30 August 2009, I (Easterla) discovered a juvenile Red-necked Stint (Calidris ruficollis), which had never been fully documented in the lower 48 states. At approximately 09:00, while scanning for shorebirds on a large mudflat at the Yolo Wildlife Area in Yolo County, California (managed by the California Department of Fish and Game), I noticed a peep, smaller than nearby Western Sandpipers (C. mauri), with a long primary projection, a full set of tertials, black legs, and a very short bill. The bird’s fresh plumage and overall scaled appearance showed it to be a juvenile. On the basis of my prior observations of juveniles of another Old World species of black-legged stint in California, the Little Stint (C. minuta), on 22 September 1994 (Howell and Pyle 1997) and 14 September 2008 (Pike and Compton 2010), as well as my experience observing stints in Europe, Russia, and southeast Asia, I felt confident this bird was a juvenile black-legged stint from Eurasia (Veit and Jonsson 1987) and probably a juvenile Red-necked Stint. Upon realizing the possibility of such a discovery, I phoned John Sterling and other birders who joined me to verify my observation.