The free portion of Empire mine is mostly brush and horsetrails, not an ATV park, there are no ATVs available. The pay-upon-entry portion of the park is a large mining exhibit with Victorian houses in their semi-original conditions. I would suggest one of the quarries around Nevada county for ATV riding, you could find them in Penn Valley or maybe even somewhere at the Greenhorn Rock Quarry. I'm not sure where you could get the ATV rentals, though.
No
Not from the parks department.
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