(Oregon, USA) Looking to catch some on our next camping trip, and get some river diving in at the same time. Please help!

While I do not know Oregon State law, I am willing to bet the answer is yes. You will likely need a fishing license and you may want to contact your state fish and wildlife about hunting crawdads while scuba diving. There are laws that concern harvesting with scuba diving and you may need to find out what they are.