Bonanza is a city in Klamath County, Oregon, United States near Klamath Falls. The population was 415 at the 2010 census.
Bonanza is an agricultural community with large areas of alfalfa, cattle, and dairy farm use. It is home to Bonanza High School, and the Lost River runs near downtown where the Bonanza Big Springs are located. Low water levels have caused groundwater contamination through the springs adding to the regional controversies over water use, endangered suckers (fish) and struggling salmon species, and farming.
Bonanza is located at the east end of Oregon Route 70, the shortest state highway in Oregon, and is approximately 25 miles from Klamath Falls.