The university defeated defending URC champions from the University of Nevada, Reno at the Mars Desert Research Station in Utah. A new team from York University of Toronto ranked third in the two-day competition last week.
Oregon State was the only team to locate a "distressed astronaut" during the navigation challenge.
"Their science payload was particularly amazing because of the way they used common household products," judge Heather Smith said in a statement on the Mars Society's Web site. "They had an electric toothbrush to clean off rocks, a standard mechanical drill, and a common thermometer. It's just a shame that their drive train failed before they could finish the event."
URC director Kevin Sloan called the event a success.
"Not only did we have more teams than last year, the overall quality of the rovers was considerably higher this year," he said in a news announcement. "All of the teams should be very proud of their rovers, and of their skills in controlling them. The level of skill on display was amazing."
Seven teams from across North America built "Mars rovers" to compete in a series of tasks that explored geology, biology, basic engineering, and construction, as well as emergency navigation.
Alan Spencer, a judge from Raytheon, said all of the teams displayed professionalism.
"These students are going to make really excellent engineers and scientists as they enter the workforce, and I think that they'll all be in better shape because of their participation this year," he said.
The Oregon State team wins cash, as well as transportation, accommodations, and admissions for five of its members to attend the Annual International Mars Society Convention in Colorado this August. All participants in the contest have been invited to give presentations about their rovers at the conference.