A Marin County Search and Rescue team of volunteers conducting a training exercise on Mount Tamalpais uncovered the body of a woman Sunday afternoon, law enforcement authorities said.

The discovery about half a mile northwest of West Blithedale Avenue's end comes five weeks after Veronica Ruiz, a 25-year-old federal tax agent, disappeared after she told friends she was going for a hike. Crews conducted an exhaustive search for Ruiz in the two days following her disappearance, then called it off. Friends and family continued to search long after the authorities suspended their official search Dec. 5. About two dozen searchers were participating Sunday in the mock exercise with nine dogs from the California Rescue Dogs Association who are trained to find cadavers when the clothed body was found at about 1:30 p.m. It was in a grove of redwood trees amid dense underbrush about 30 to 40 yards off Hoo-Koo-E-Koo Road near West Blithedale Ridge in Mt. Tam State Park, Marin County sheriff's spokesman Lt. Doug Pittman said.

Pittman said the Marin County Coroner's Office is investigating the identity of the woman and cause of death. He said it might take a few days. Ruiz's family and friends have been notified of the discovery, Mill Valley police detective Lindsay Haynes said.

Sunday night, the Web site set up by Ruiz's friends and family acknowledged the finding of the body. "A body has been discovered ... coroner is working to match dental records," an entry said on www.helpfindveronicaruiz.com.