The term 'Humboldt River City on the' is completed by the four-letter word 'Elko'. Elko is a city in Nevada, United States, located along the Humboldt River. It is the county seat of Elko County and is the largest city in Northeastern Nevada. Elko is home to many casinos, hotels, and other tourist attractions. It is also known for its mining industry, which has been a major source of employment for the city since its founding in 1868.