Expecting a rowdy weekend because Halloween was on a Saturday this year, San Luis Obispo police and other local law enforcement agencies boosted their presence around Cal Poly and downtown.
Though crowds weren't comparable to other busy festive weekends such as Mardi Gras, they arrested 33 people for alcohol-related and other offenses.
"We had a big presence in the neighborhoods, and we did everything we could to send a message that alcohol abuse and dangerous behavior wasn't going to be tolerated," San Luis Obispo police Sgt. Janice Goodwin said.
Friday and Saturday nights were nearly three times as busy as a typical weekend while classes are in session at Cal Poly, she said.
The department averages six or seven arrests per night on typical weekends, Goodwin added.
She said that about 60 percent of arrests were for public drunkenness, while the rest were fighting or assault, plus one drunken driving arrest.
Many of the arrests were made in the neighborhoods surrounding Cal Poly, where a crowd estimated at more than 1,000 gathered on Hathaway Avenue.
Still, the crowd size and violence never approached the levels of 2004, when more than 200 people were arrested in a Mardi Gras riot in the same neighborhood.
"We certainly put a higher concentration (of our forces) out in those neighborhoods because that's where we have the least amount of control over what happens there," Goodwin said. "Those are private residences. The business owners take responsibility for what happens in their establishment."
Goodwin said her department worked at almost maximum capacity and that several officers worked overtime or adjusted schedules. Two extra patrol cars and four officers were designated to patrol the neighborhoods near Cal Poly.
The CHP, Cal Poly's University Police Department and the Union Pacific Railroad police helped San Luis Obispo officers in the weekend crackdown.
Downtown, while there was a high concentration of people on Saturday night, the scene was comparably mellow.
The flow of alcohol was somewhat slowed by the fact that people trying to get into bars were in for a typical wait time of up to 40 minutes.
"Downtown is packed - it's out of control," Cal Poly graduate Ryan Philpott said. "Everyone is just trying to get into the bars."
Philpott said he and his group of friends came downtown not to go barhopping, but to look at all the outrageous costumes.
During his time as a student, he lived just a block away from where the larger crowds were gathered Saturday night.
"It's so much different being (downtown)," Philpott said. "People are nuts out here, but it's so much less crazy than it is (near Cal Poly)."