Alaska Lt. Gov. Mead Treadwell formally announced Tuesday that he will challenge Democratic Sen. Mark Begich next year.

His candidacy, which has been expected for some time, gives Republicans a top-tier opponent in one of the party’s best pickup opportunities in the country.

“I’ve met with community and business leaders, elected officials, and my party’s grassroots volunteers from all across Alaska,” Treadwell said in a statement. “In Washington, D.C., I’ve met with members of the U.S. Senate and respected national organizations and groups that share my core conservative values. I’ve talked and prayed with my family. Their responses have been positive and encouraging.”

In the GOP primary, Treadwell must contend with tea party favorite Joe Miller. Miller, an attorney, won the 2010 Senate nomination over incumbent Sen. Lisa Murkowski, but she ran a successful write-in campaign in the general to win re-election.

(See also in Roll Call: Miller: GOP Establishment Not ‘Terribly Excited To See Me’)

Rothenberg Political Report/Roll Call rates the race Tossup/Tilt Democrat.