The Rock Sandpiper is among the most variable of sandpipers, showing a great deal of variation in size and color pattern amongst its isolated populations. The largest and brightest birds breed in the central portion of the range, while the smallest and darkest live in the southern and western part of the range.
The oldest recorded Rock Sandpiper was at least 7 years, 4 months old when it was found in Alaska, the same state where it had been banded.