South Dakota·SD·FIPS 46103

Pennington County

Voted Republican in 2024 · 56,580 votes cast

About Pennington County

Pennington County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 109,222, making it the second most populous county in South Dakota, and was estimated to be 116,792 in 2025. Its county seat is Rapid City. The county was created on January 11, 1875, and was organized on April 19, 1877. It is named for John L. Pennington, fifth Governor of Dakota Territory, who held office in 1875 when the county was formed. Pennington County is included in the Rapid City metropolitan statistical area. It is also the location of Mount Rushmore.

2024 Presidential Results

All candidates · Pennington County, South Dakota

Donald J Trump(Republican)

61.9%35,009

Won by 14,958 votes

Kamala D Harris(Democrat)

35.4%20,051

Other(Other)

1.8%1,037

Chase Oliver(Libertarian)

0.9%483

Margin History

Red = Republican, Blue = Democratic

2024R+26.4

2020R+25.1

2016R+32.9

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Swung Right in 2024

Pennington County shifted 1.3 points toward Republicans compared to 2020. Voter turnout decreased by 1.6%.

Pennington County — Local Discussion

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What does Pennington County really think?

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Election data: MIT Election Data Science Lab, Harvard Dataverse (CC BY 4.0)