MONROE, Wash. (CBS) — Employees at a Monroe Goodwill opened up a donated cooler to find a unique surprise.

About 3.75 pounds of marijuana were found inside the container that was donated to the thrift store over the weekend. That’s an estimated street value of $24,000, according to police.

Monroe police were called to investigate. So far the person who donated the cooler has not been identified.

While marijuana is legal in the state of Washington, adults can only purchase and possess up to 1 ounce of weed.