Nice catch, Drako! As a Corvallis resident and fly-fisher, I’ve always been a bit curious about Oak Creek, but ultimately turned off from fishing it; just seems like too small of a creek that receives a lot of urban chemical runoff and impact from agriculture. While it’s not listed as closed in the reg book (to my knowledge), it just never felt morally right to fish it when there are other healthier, less fragile systems nearby.
That said, I’m impressed you caught that cutthroat in the low waters of August! Try fishing it with bright flies this winter? Often, big trout come up creeks like that from the Willamette during heavy rainfall. Have fun.