Lawrence County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 25,768, making it the 8th most populous county in South Dakota. Its county seat is Deadwood.

Lawrence County is coextensive with the Spearfish, SD Micropolitan Statistical Area, which is also included in the Rapid City-Spearfish, SD Combined Statistical Area.

Lawrence County was created January 11, 1875, and was organized in 1877. The county was named for "Colonel" John Lawrence, who came to the county as first treasurer in 1877. Lawrence had previously served in the Dakota Territorial Legislature, as a Sergeant at Arms for the United States House of Representatives, and a US Marshal for the Dakota territory. After retirement, he continued to act as county road supervisor and as an election judge. The title "Colonel" was honorary, bestowed by the governor of the Dakota Territory.

Lawrence County lies on the west side of South Dakota. Its west boundary line abuts the east boundary line of the state of Wyoming. The terrain of Lawrence County consists of mountains in the south and west, falling off to the hilly northeast portion. A tributary of the Redwater River flows east-northeasterly along a portion of the county's north boundary line, delineating that portion of the line. The terrain generally slopes to the county's northeast corner; its highest point is Crooks Tower, at 7,137'. The county has a total area of 800 square miles (2,100 km), of which 800 square miles (2,100 km) is land and 0.3 square miles (0.78 km) (0.03%) is water.

• Jefferson Lines

• Black Hills National Forest (partial)
• Beilage Hepler State Game Production Area
• Coxes-Mirror Lakes State Game Production Area
• Harrison-Badger-Trucano State Game Production Area
• Iron Creek Lake State Game Production Area
• Reausaw Lake State Game Production Area
• Spearfish Canyon State Nature Area

Historical population

Census	Pop.	Note	%±
1880	13,218		—
1890	11,673		−11.7%
1900	17,897		53.3%
1910	19,694		10.0%
1920	13,029		−33.8%
1930	13,920		6.8%
1940	19,093		37.2%
1950	16,648		−12.8%
1960	17,075		2.6%
1970	17,453		2.2%
1980	18,339		5.1%
1990	20,655		12.6%
2000	21,802		5.6%
2010	24,097		10.5%
2020	25,768		6.9%
2023 (est.)	28,053		8.9%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2020

As of the 2020 census, there were 25,768 people, 11,444 households, and 6,689 families residing in the county. The population density was 32.2 inhabitants per square mile (12.4/km). There were 14,163 housing units.

The county population contained 23.10% under the age of 18, 13.70% from 18 to 24, 25.40% from 25 to 44, 23.10% from 45 to 64, and 14.60% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 96.80 males. For every 100 females age 18 and over, there were 93.30 males.

The median income for a household in the county was $31,755, and the median income for a family was $40,501. Males had a median income of $30,098 versus $19,679 for females. The per capita income for the county was $17,195. About 9.50% of families and 14.80% of the population were below the poverty line, including 15.70% of those under age 18 and 9.10% of those age 65 or over.

As of the 2010 census, there were 24,097 people, 10,536 households, and 6,181 families in the county. The population density was 30.1 inhabitants per square mile (11.6/km). There were 12,756 housing units at an average density of 15.9 per square mile (6.1/km). The racial makeup of the county was 94.4% white, 2.0% American Indian, 0.7% Asian, 0.4% black or African American, 0.5% from other races, and 2.0% from two or more races. Those of Hispanic or Latino origin made up 2.5% of the population. In terms of ancestry, 44.5% were German, 13.7% were Irish, 13.4% were English, 11.4% were Norwegian, and 4.4% were American.

Of the 10,536 households, 24.0% had children under the age of 18 living with them, 46.6% were married couples living together, 8.1% had a female householder with no husband present, 41.3% were non-families, and 33.2% of all households were made up of individuals. The average household size was 2.19 and the average family size was 2.77. The median age was 41.0 years.

The median income for a household in the county was $42,356 and the median income for a family was $60,209. Males had a median income of $38,933 versus $28,649 for females. The per capita income for the county was $25,465. About 8.4% of families and 15.3% of the population were below the poverty line, including 15.8% of those under age 18 and 8.1% of those age 65 or over.

• Boulder Canyon
• Crook City
• Mountain Plains
• North Spearfish
• Saint Onge

• St. Onge Township
• North Lawrence (unorganized territory)
• South Lawrence (unorganized territory)

Owing to its Yankee influence, Lawrence County has been reliably Republican for a full century. It was the only South Dakota county to remain loyal to Herbert Hoover in his landslide 1932 loss. In fact, Lawrence County was the second-westernmost county, behind only Utah's Kane County, to never vote for Franklin D. Roosevelt. The only Democratic presidential candidates to carry Lawrence County have been Woodrow Wilson in 1912 and 1916, and William Jennings Bryan in 1896. Lawrence County has also been one of the most consistent strongholds for the Libertarian Party, giving their 2016 nominee, Gary Johnson, one of the largest vote share out of any county outside his home state of New Mexico, with 7.9%. In 2020, Libertarian Party nominee Jo Jorgensen received 3.9% of the popular vote, her second best performance in any county during the election cycle.

United States presidential election results for Lawrence County, South Dakota

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2020	8,753	63.30%	4,537	32.81%	538	3.89%
2016	7,411	62.58%	3,356	28.34%	1,075	9.08%
2012	7,025	61.85%	3,973	34.98%	361	3.18%
2008	6,787	56.30%	4,932	40.91%	336	2.79%
2004	7,489	64.45%	3,857	33.20%	273	2.35%
2000	6,327	67.27%	2,797	29.74%	282	3.00%
1996	4,430	46.92%	3,568	37.79%	1,444	15.29%
1992	3,770	39.03%	3,157	32.68%	2,732	28.28%
1988	5,570	59.39%	3,705	39.50%	104	1.11%
1984	5,949	69.42%	2,565	29.93%	55	0.64%
1980	5,306	63.14%	2,259	26.88%	838	9.97%
1976	4,206	56.46%	3,102	41.64%	141	1.89%
1972	4,795	65.22%	2,533	34.45%	24	0.33%
1968	4,185	60.23%	2,425	34.90%	338	4.86%
1964	3,743	51.91%	3,468	48.09%	0	0.00%
1960	5,083	66.06%	2,612	33.94%	0	0.00%
1956	4,654	71.33%	1,871	28.67%	0	0.00%
1952	5,559	76.57%	1,701	23.43%	0	0.00%
1948	3,778	62.50%	2,209	36.54%	58	0.96%
1944	3,528	65.41%	1,866	34.59%	0	0.00%
1940	5,288	60.07%	3,515	39.93%	0	0.00%
1936	4,974	56.19%	3,809	43.03%	69	0.78%
1932	3,708	53.99%	3,106	45.22%	54	0.79%
1928	4,141	69.63%	1,785	30.02%	21	0.35%
1924	3,255	71.07%	649	14.17%	676	14.76%
1920	2,986	68.50%	1,201	27.55%	172	3.95%
1916	2,074	47.51%	2,157	49.42%	134	3.07%
1912	0	0.00%	2,412	53.95%	2,059	46.05%
1908	2,735	50.86%	1,564	29.09%	1,078	20.05%
1904	4,247	65.53%	1,347	20.78%	887	13.69%
1900	3,435	55.96%	2,619	42.67%	84	1.37%
1896	2,210	42.91%	2,905	56.41%	35	0.68%
1892	2,140	51.18%	546	13.06%	1,495	35.76%

School districts include:

• Belle Fourche School District 09-1
• Lead-Deadwood School District 40-1
• Meade School District 46-1
• Spearfish School District 40-2

• List of Superfund sites in South Dakota
• National Register of Historic Places listings in Lawrence County, South Dakota

• Caddey, S.W. et al. (1991). The Homestake Gold Mine, an Early Proterozoic iron-formation-hosted gold deposit, Lawrence County, South Dakota [US Geological Survey Bulletin 1857-J]. Washington DC: US Department of the Interior, US Geological Survey.

• Media related to Lawrence County, South Dakota at Wikimedia Commons
• Lawrence County, SD government website

44°22′N 103°47′W / 44.36°N 103.79°W / 44.36; -103.79