This common name refers to only one family.
These are pretty much always called Snowflies.
These are the first stoneflies of the year to appear in most parts of the country, and often the first aquatic insects noticed by the angler. Their dark brown or black bodies are easy to spot against the snowbanks where they crawl around.
in the West and Allocapnia
in the East are probably the most common genera of this prolific family.