Three men believed to be responsible for a September heist of about $1.3 million in precious gems and gold from a mining museum in the Sierra Nevada foothills have been arrested, the California Highway Patrol said Tuesday.

State and local law enforcement officials served warrants Tuesday morning in Sacramento, El Dorado and Sutter counties and arrested Jonathan Matis, 41, Matthew Campbell, 43, and Edward Rushing III, 40, in connection with the robbery of the California Mining and Minerals Museum in Mariposa, said Lt. Mike Troxell, a CHP spokesman.

Matis and Campbell were arrested on suspicion of robbery and other charges, while Rushing was taken into custody on suspicion of multiple felonies, including drug charges, Troxell said.

The arrests come after a brazen Sept. 28 heist when robbers, wearing hoods and armed with pickaxes, smashed display cases to rob the museum while it was open for business.

The museum is home to more than 13,000 artifacts, including the Fricot Nugget, a nearly 14-pound crystalline gold mass. The robbers weren't able to make off with the rock because they triggered an alarm that alerted authorities, who swarmed the museum but were unable to nab the thieves at the time.

The two employees who were in the museum during the robbery were not hurt but were shaken from the experience, the California Department of Parks and Recreation, which operates the facility, said after the robbery.

Officials initially said the thieves stole about $2 million in gems and gold, but after an inventory by museum officials, it was determined that about $1.3 million was stolen, Troxell said. CHP investigators were questioning the three suspects late Tuesday to try to determine if others were involved in the heist, Troxell said. The CHP is investigating because the robbery took place on state property.

At the time it was the second heist of the year of rare, valuable metals in Northern California. In February, thieves made off with large chunks of gold that were on display in a Siskiyou County courthouse.