Population of Counties in Montana (2019)

Name 2019 Population Growth Since 2010
Yellowstone County160,1377.92%
Missoula County118,7918.52%
Gallatin County111,87624.79%
Flathead County102,10612.37%
Cascade County81,6430.17%
Lewis and Clark County68,7008.06%
Ravalli County43,1727.06%
Silver Bow County34,9932.22%
Lake County30,2505.07%
Lincoln County19,7940.50%
Park County16,7367.28%
Hill County16,3471.20%
Glacier County13,7472.44%
Big Horn County13,3383.28%
Jefferson County12,0976.04%
Sanders County11,8443.93%
Custer County11,586-0.92%
Fergus County11,113-4.10%
Roosevelt County11,0595.89%
Richland County10,91311.82%
Carbon County10,7146.47%
Stillwater County9,5344.51%
Beaverhead County9,4041.61%
Deer Lodge County9,131-1.70%
Rosebud County9,063-2.04%
Madison County8,76813.91%
Dawson County8,680-3.02%
Valley County7,4370.80%
Powell County6,968-0.73%
Blaine County6,8074.67%
Teton County6,1621.45%
Broadwater County6,0858.04%
Pondera County5,972-3.07%
Chouteau County5,745-1.12%
Toole County4,853-9.17%
Musselshell County4,6512.11%
Mineral County4,3162.13%
Phillips County4,074-4.19%
Sweet Grass County3,7102.49%
Sheridan County3,4241.66%
Granite County3,3789.68%
Fallon County2,9201.07%
Liberty County2,4303.45%
Wheatland County2,2363.71%
Judith Basin County1,952-5.79%
Meagher County1,866-0.64%
Daniels County1,747-0.11%
Powder River County1,716-1.32%
McCone County1,675-4.01%
Garfield County1,2686.38%
Carter County1,2386.72%
Prairie County1,087-8.11%
Wibaux County1,0342.68%
Golden Valley County826-6.03%
Treasure County679-5.43%
Petroleum County5134.91%