Jon Tester, a conservative Democrat:
Sen. Tester sponsored the controversial measure that took Northern Rockies wolves off the endangered species list in 2011 -- a move praised by ranchers and elk hunters. It triggered disagreements among environmentalists. (Some liked it and some condemned it.) He also:
• Sponsored a bill that guaranteed 678,000 acres of wilderness while attempting to guarantee logging on 10,000 acres of federal land per year; and
• Co-sponsored The Sportsmen's Act of 2012, a pro-gun, pro-hunting measure that includes funding for conservation projects.
• He's the only Democratic senator who voted against the Wall Street bailout, but wants tougher regulation of the bankers.
• He voted for Obama's health-insurance reforms, but won't attend the Democratic Party's national convention in North Carolina in September, to emphasize his independence.
• Like Rehberg, he supports construction of the Keystone XL pipeline to flow Canadian tar-sands crude to refineries on the Gulf of Mexico coast, over the objections of environmentalists.
• According to the League of Conservation Voters, Tester votes green at least 83 percent of the time.
Denny Rehberg, a conservative Republican:
Rep. Rehberg hasn't created any high-profile laws in his 12 years in the House. According to OpenCongress.org, none of the 20 bills he sponsored passed, and only eight of the 189 he co-sponsored did. Some highlights:
• When asked to name his greatest achievement, during the Big Sky debate with Tester in June, he cited a measure that created a commemorative coin made of palladium from a Montana mine.
• He's now co-sponsoring a bill that would allow the Department of Homeland Security to override other federal agencies in managing national forests and parks near the Canadian border.
• He opposes Tester's wilderness-jobs bill as unfair to off-road drivers, and wants to end protection of 43 million acres of wilderness-study areas.
• He opposes tougher regulations on Wall Street banks, as well as Obama's health-insurance reforms.
• He wants to require federal agencies to get congressional approval for major regulations, putting them on a tight leash. (The House passed the 2011 bill, but it's stalled in the Senate.)
• According to the League of Conservation Voters, Rehberg votes green only 9 percent of the time.