Student Missing After Houseboat Party

California authorities are looking for an Oregon State University student who disappeared after she was seen arguing with her boyfriend.

Police said Gina Zalunardo, 22, was last seen Saturday night at a houseboat party in Shasta Lake, Calif. Zalunardo, a junior majoring in international business at Oregon State University, had been arguing with her boyfriend that night and got separated from a group of students who were vacationing on the houseboat. A friend reported Zalunardo missing on Sunday morning after searching for her overnight.

However, Shasta County Sheriff's Department Sgt. Mark Lillibridge said the boyfriend -- whose name has not been released -- is not considered a suspect in Zalunardo's disappearance and foul play is not suspected.

Popular Vacation Getaway for Students

Lillibridge said there did not seem to be unusual activity reported at Shasta Lake, which has been an attraction for students looking for a getaway around this time of the year.

"This is the time of the year that the college kids come out usually from Oregon State University," he said Monday. "They pick other dates each year, and it's been a tradition for several years. They [the students] have about 40 boats that went out [over the weekend] and I would say approximately 50 kids that showed up. … We basically had one of the most uneventful college weekends that we've ever had. We had one assault. We didn't have any medical issues to speak of."

The houseboat where Zalunardo was last seen was anchored at Slaughterhouse Island near where the Sacramento and Pit rivers flow into Shasta Lake. Volunteers and search and rescue officials have been searching the island and using submersible cameras to search Shasta Lake since Sunday.

Anyone with information on Zalunardo's whereabouts is asked to call the Shasta County's Sheriff's Department at (530) 245- 6540.

ABC News Affiliate KRCR in Redding, Calif., contributed to this report.