The only Oregon minnows that look similar are lake chubs, so they're my leading contender by default. And while trout would certainly fit the habitat, these really don't look like any fingerlings I've seen. The black stripe is also much more pronounced than I've seen on local speckled or longnose dace.
The photos weren't taken by me and I've cropped them to focus on the fish, sorry about the quality. They come from a hiking website and the fish were included incidentally.