President Barack Obama interviewed federal appeals court Judge Sidney Thomas of Montana yesterday for an opening on the Supreme Court, a person familiar with the conversation said.

The roughly hourlong session at the White House was the first known formal interview that Obama has conducted for the upcoming vacancy on the high court. It is not clear whether Obama has interviewed other candidates in person.

Vice President Joe Biden also interviewed Thomas at the White House in a separate meeting yesterday, said the person familiar with the conversations, who spoke on condition of anonymity in order to discuss Obama's private deliberations.

The White House had no comment.

The news of his interview by the president and vice president works to the White House's advantage in signaling that Obama is giving a hard review to a candidate who comes from outside the Washington Beltway and does not fit neatly into conventional wisdom.

The court is dominated by justices with ties to the Northeast and the Ivy League; Thomas' career is rooted in the West—he lives in Billings, Mont., and got his bachelor's degree from Montana State University and his law degree from the University of Montana.

The 56-year-old judge serves on the 9th U.S. Circuit Court of Appeals, the largest of the nation's appellate courts, which covers Hawaii. He was nominated to that job in July 1995 by President Bill Clinton and confirmed by the Senate with no controversy.

The San Francisco-based appeals court on which he serves has a liberal reputation, but attorneys who know Thomas describe him as independent and a straight shooter.

Obama is choosing a nominee to replace Justice John Paul Stevens, who is retiring this summer.

Thomas' name has been on Obama's known list of court contenders for more than two weeks. But the intense speculation about whom Obama will pick has centered on other names—chiefly Solicitor General Elena Kagan and federal appeals court judges Diane Wood and Merrick Garland.

The president has been considering about 10 people as potential nominees.