Joseph Creek salmonid populations (including all tributaries from mouth to headwaters). Joseph Creek originates in the North Eastern corner of Oregon on the south flank of Blue Mountains and North Wallowa Mountains and flows north into Washington State and drains into the lower Grande Ronde River. The creek was supports a population of Snake River ESU steelhead and spring Chinook with estimated potential population exceeding 500 adults for each species. As a result the creek was identified as a Major Spawning Aggregation for steelhead. Joseph Creek flows a relatively short distance through Washington State and only the lowest reach of the river flows through the state. As a result the reach was given a priority protection designation to maintain flow, water quality and to prevent imminent threats in the lower river.