Sweet Grass, MT has a population of 95 and is the 27,071st largest city in the United States. The population density is 193 per sq mi which is 2719% higher than the Montana average and 113% higher than the national average. The median age in Sweet Grass is 37 which is approximately 7% lower than the Montana average of 40. In Sweet Grass, 71% of the population over 15 years of age are married, 94% speak English and 0% speak Spanish. 33% of Sweet Grass residents were born in Montana, 67% were born out of state, 0% were born outside of the United States and 0% were foreign born.