That was my thought exactly, but I was less eager to share. Gold is often found in association with serpentine (I would bet that has something to do with it being California's state rock) and I saw a lot of serpentine in that gouge caused by the side offshoot. Oroville is not too far from Sutter Mill, where gold was first discovered in California. The Feather River is one of the main river systems in what is known as the 'Mother Lode' area of California (yes, that is where that phrase comes from).
minor footnote: serpentine is interesting as the state rock and a host for gold, and also as a host for chrysotile asbestos. there was some discussion five or ten years back about changing California's state rock to something else because of that.
