The size of Lost River is approximately 115.9 square kilometres. It has 5 parks covering nearly 0.2% of total area. The population of Lost River in 2011 was 476 people. By 2016 the population was 66 showing a population decline of 86.1% in the area during that time. The predominant age group in Lost River is 50-59 years. Households in Lost River are primarily childless couples and are likely to be repaying under $300 per month on mortgage repayments. In general, people in Lost River work in a managers occupation. In 2011, 83.5% of the homes in Lost River were owner-occupied compared with 81.8% in 2016.