Subject
- Agricultural pollution -- Oregon -- Umatilla River -- Evaluation1
- Bacterial pollution of water -- Oregon1
- Indicators (Biology) -- Oregon -- Umatilla River1
- Mayflies -- Larvae -- Effect of temperature on1
- Recreation areas -- Health aspects -- Oregon1
- Rivers -- Oregon -- Recreational use1
- Stream invertebrates -- Oregon -- Umatilla River1
- Water quality biological assessment -- Oregon1
- Water quality biological assessment -- Oregon -- Umatilla River1