A man and woman sought on suspicion of passing counterfeit currency in the Black Hills area were arrested Thursday at the Best Western Travelodge in Spearfish.

Sean Woodward, 40, and Resa Woodward, 46, both of Los Angeles, were arrested on suspicion of manufacturing and passing counterfeit U.S. currency.

Spearfish Police Chief Pat Rotert said officers went to the hotel where the Woodwards were staying after getting a tip that two people there matched the description of the people suspected of passing the fake money.

Rotert said officers seized equipment used for producing counterfeit money, an undisclosed amount of counterfeit currency and numerous documents showing the suspects operating within a large regional geographic area including the Black Hills.

Rotert said the counterfeit bills were actual $5 bills converted to look like $50 bills.

He said the bills pass marker tests for authenticity but may have a visible watermark of Abraham Lincoln in the right-hand area of the bill, which is only present on a $5 bill.

Rotert said that to see the watermark, the bill must be held up to a light.

A genuine $50 bill will have a Ulysses S. Grant watermark.

Rotert said area businesses are encouraged to scrutinize any $50 bills for authenticity.

Rotert said the Woodwards are in custody at Lawrence County Jail. U.S. Secret Service agents were contacted to coordinate the federal investigation into the activity.