Subject
- Mineral industries -- Oregon17
- Natural gas -- Prospecting -- Oregon15
- Petroleum -- Prospecting -- Oregon15
- Geology -- Oregon -- Field work5
- Geothermal resources -- Oregon5
- Metallurgy -- Oregon4
- Metallurgical plants -- Oregon2
- Earthquakes -- Oregon1
- Geology -- Oregon -- Wasco County1
- Geothermal resources1
- Groundwater -- Oregon -- Wasco County1
- Manganese nodules -- Composition1
- Mercury industry and trade -- Oregon1
- Mercury mines and mining -- Oregon1
- Metal trade -- Oregon1
- Mineral industries -- Economic aspects -- Oregon1
- Mineral industries -- Government policy -- Oregon1
- Mines and mineral resources1
- Mining law1
- Surface fault ruptures -- Oregon -- Christmas Lake Valley1