Deputies raided a cockfighting venue and found dozens of live and dead roosters near Grayson on Sunday afternoon, the Stanislaus County Sheriff's Department reported.
More than 50 men ran from the scene as deputies arrived about 1 p.m. to investigate a report of cockfighting near 11000 Cox Road, the report said.
Some of the men jumped into the San Joaquin River, authorities said. No arrests were reported as of Sunday evening.
Deputies found more than 35 live roosters in wooden boxes in an old building and about 50 dead birds inside and outside, the report said.
The Stanislaus Animal Services Agency was called to assist in the investigation.
A state law that took effect this year doubled the maximum fine for cockfighting to $10,000 and raised the fines for initiating other forms of animal fighting or attending such events.
The raid came four days after federal agents arrested three Tracy residents on suspicion of taking part in a major dogfighting operation. They and others were arrested in the aftermath of a raid on a Mississippi barn where a large annual dogfighting event was reportedly being held.
Anyone with information about the cockfighting case can call the Stanislaus County Sheriff's Department at (209) 525-7114. Anonymous tips can be made by calling Crime Stoppers at (209) 521-4636, visiting www.modestopolice.com/CrimeStoppers or by texting CRIMES (274637) by typing "Tip704" plus a message. Tipsters could be eligible for a cash reward.