DemographicsSpring Mountain (NSW) is approximately 63.71 square kilometres. In 2016 the population of Spring Mountain (NSW) was 20. The population is 65% male and 35% female. On average the monthly mortgage repayments in Spring Mountain (NSW) are $0 to $299. The most common weekly income bracket is $800 to $999 per week. Weekly rents in the area are on average $0 to $74.