(CNN) Oregon State University has temporarily stopped harvesting old trees in its research forests after a Douglas fir that was around 420 years old was cut down.

Cutting down such an old tree -- part of a stand of trees in the school's McDonald and Dunn Research Forests , near the university's campus in Corvallis -- was a mistake, a school official acknowledged.

"For years we've had plans that these trees would be harvested," Anthony Davis, the interim dean of the university's College of Forestry, told CNN, referring to a forest management plan that the school has been using since 2005. "Our mistake was in sticking to that."

The harvesting of the more than 400-year-old tree, as well as other trees in the stand between 80 to 260 years old, occurred a little over a month ago. It's part of the logging activities conducted in the university's research forests that generate about $1 million a year in revenue for the College of Forestry.

Davis said people who use the forest for recreation were concerned that such old trees were being harvested and reached out to Davis and other school officials with their concerns.

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