I believe this to be a juvenile mountain whitefish but I am not particularly familiar with fish, so please correct it if I am wrong. See video on YouTube here: https://youtu.be/AUet0AiWYPM
might not be this fish not sure
Spawning White Suckers >50, males with a strip
Many of them about a foot long. Some had distictive black strip with orange on top of the strip on the sides of the body. Non-striped ones were grey.
White or perhaps longnose sucker. It's a challenge to get photos of fish in a stream. Cold headwater stream. Seem to be spawning.