Epeorus albertae

[Mark Melton]

These nymphs are found in the Russian River from late February through August. They're found in fast water with large gravel and cobbles. They're about 12 mm long (not including cerci) at maturity.

 

[FinLuver]

These what they call “clingers”…?

 

[Mark Melton]

Yeah, they'd be called clingers. They tend to move to different areas by letting go of whatever they have hold of and letting the current take them.