Always challenging to know which yellowlegs, greater or lesser? This one is a greater and was seen & verified by several other people and sites. Lesser yellowlegs are slimmer with a bill that is slightly longer than its head. Greater yellowlegs are larger, bulkier and have a bill that is 1.5 times the length of its head. The bird at the bottom is a least sandpiper, left in the shot for size comparison. Even though closer to the camera, the sandpiper is still so much smaller.
Least Sandpiper (Calidris minutilla)
Greater Yellowlegs (Tringa melanoleuca)