Floriston is an unincorporated community and census-designated place in Nevada County, California. It is situated at an elevation of 5,400 ft above sea level. Floriston is located on the Truckee River, 10 miles east-northeast of Truckee. Formerly an important railroad stop and mill town, Floriston survives to this day as a small residential community. The p…Floriston is an unincorporated community and census-designated place in Nevada County, California. It is situated at an elevation of 5,400 ft above sea level. Floriston is located on the Truckee River, 10 miles east-northeast of Truckee. Formerly an important railroad stop and mill town, Floriston survives to this day as a small residential community. The population was 73 at the 2010 census.