Au Sable, MI has a population of 1,322 and is the 13,459th largest city in the United States. The population density is 630 per sq mi which is 525% higher than the Michigan average and 596% higher than the national average. The median age in Au Sable is 48 which is approximately 21% higher than the Michigan average of 40. In Au Sable, 62% of the population over 15 years of age are married, 97% speak English and 0% speak Spanish. 76% of Au Sable residents were born in Michigan, 22% were born out of state, 1% were born outside of the United States and 2% were foreign born.