CHEYENNE, Wyo. — A federal indictment charges a Sheridan couple with tax evasion and conspiring to defraud the IRS by concealing money in a bank account in the Caribbean island of Nevis.

Robert Sathre and Judy Sathre pleaded not guilty to the charges before a federal magistrate on Wednesday. Attempts to reach them and their attorney, Craig Silva of Casper, for comment Friday were unsuccessful.

The indictment alleges that Robert Sathre had owned 90 percent of a Minnesota business called Industrial Custom Products Ltd. It states he received installment payments of more than $3 million in 1995 and 1996 from the sale of the ICP stock but reported only about $65,000 on his 1995 tax return.

Robert Sathre purchased property in Sheridan in 1996 and operated a gas station/convenience store there called the Rock Stop, the indictment says. It states that the couple opened an account at the Bank of Nevis in 1996.

The indictment states Robert Sathre falsely claimed he was neither a citizen nor a resident of the United States when he opened a checking account at Sheridan State Bank in 1998.

Robert Sathre sold the Rock Stop in 2007 for $2 million, the indictment alleges, and put about $1.25 million of the proceeds into the trust account at an unspecified Wyoming law firm.

Robert Sathre sent a letter in May 2007 to the law firm requesting the transfer of $900,000 to the account in Nevis, the indictment states. It says he instructed the firm, "DO NOT show our Bank of Nevis account number nor our names on your wire instructions for privacy reasons."

Judy Sathre gave the Bank of Nevis a "false declaration" in July 2007 claiming that the $900,000 was from the payment of a promissory note, the indictment alleges. It states Robert Sathre later obtained a Bank of Nevis debit card that allowed him to access the cash.

The indictment also charges Judy Sathre with making a false tax return, stating that she failed to disclose in 2007 that she had signatory authority over the account in Nevis.

The indictment states that the couple tried to conceal their ownership of real estate through trusts. It charges that they mortgaged their home in Sheridan to another company they were involved with called New West Investments and states that Robert Sathre transferred title to real estate in Hennepin County, Minn., to the company.

The couple is set to stand trial on Aug. 21 before U.S. District Judge Alan B. Johnson of Cheyenne. The case is being prosecuted by lawyers with the U.S. Department of Justice's Tax Division and was investigated by the IRS.