After more than 20 years of ownership, Dyno Nobel has sold its nitrogen manufacturing plant north of St. Helens to Columbia River Nitrogen.

The plant has been in operation for 60 years and was purchased by Dyno Nobel in 2003. The sale was finalized at the end of last month.

Dyno Nobel said the change in ownership will not affect employees. Company president Greg Hayne called it “an important transaction that aligns with our overall business strategy,” and said the agreement will ensure continued operation of the plant, which is vital to employees, their families, and the local community.

The plant has played a major role in Columbia County’s economy. In 2024, Dyno Nobel was the county’s sixth-highest taxpayer, paying more than $880,000.