Portnuef River camping in March

It has been a cold wet March. I went camping about a mile from where
Mink Creek converges with the Portnuef River. Canadian geese families
and mule deer families visited the potato field next to the river while I
walked looking for signs of active beaver. I saw the signs of beaver
activity. I also saw little red bellied trout jumping in the river.
Are they cutthroats?