This is the reason most people stop in Jamestown. Railtown 1897 preserves the original Sierra Railway shops and roundhouse, built when this stretch of the Mother Lode was still a working gold and timber economy. Six locomotives are kept in operating condition, including Sierra No. 3, the most filmed steam engine in the world. The roundhouse tour walks you through the blacksmith shop, the belt-driven machine tools, and the engine pits — all original, all still functional.
On weekends from April through October the park runs short steam excursions through the foothills behind town, with a brief stop in oak savannah. The ride is unhurried, the carriages are open-window, and a volunteer interpreter rides along to explain what you're looking at. Allow two hours for the museum plus excursion, longer if you want to time it with one of the seasonal "Behind the Roundhouse" extended tours.