At about 12:15 p.m., the motorcyclist and his 1999 Harley Davidson Sportster traveled off of the roadway on Calaveras Boulevard, north of Felter Road, CHP Officer Eric Anderson said.
For an unknown reason, the motorcyclist unsuccessfully navigated a bend in the road and fell 30-feet down a bordering cliff, Anderson said. The man was pronounced dead at the scene, he said.
The motorcyclist was a resident of Twain Harte, a town bordering Stanislaus National Forest, CHP said.
The victim's identity remains under investigation, pending autopsy results from the Santa Clara County medical examiner's office.
CHP said that there were no other vehicles involved in the crash.
Calaveras Road was closed in both directions in the area for two and a half hours due to the fall, CHP Officer Scott Cakebread said.
It is unknown whether alcohol, drugs, or reckless driving played a role in the crash, Cakebread said.