The Nevada County Narrow Gauge Railroad (NCNGRR) (nickname: Never Come, Never Go) was located in Northern California’s Nevada County and Placer County, where it connected with the Central Pacific Railroad. The Nevada County Narrow Gauge Railroad Company incorporated on April 4, 1874, and was headquartered in Grass Valley, California. After two years of construction, passenger and commercial rail services began in 1876 and continued until 1943. The 22.53 mi (36.26 km) line ran from Colfax, north through Grass Valley to Nevada City. At one time, the railroad was notable for having the highest railroad bridge in California, the Bear River Bridge, built in 1908. – https://en.wikipedia.org/wiki/Nevada_County_Narrow_Gauge_Railroad
The photo below is of Shebley’s trestle, located at the very North end of what now is Rollins Lake.