Rapid City's location on the boundary of the Western and Eastern power grids, together with the hydroelectric plants of the Mainstem Dams on the Missouri River and the large coal fields and power plants of the Powder River Basin of Wyoming make it one of the points where the two national power grids connect with each other, allowing switching of electrical power from east to west and vice versa.

Rapid City's location on the boundary of the Western and Eastern power grids, together with the hydroelectric plants of the Mainstem Dams on the Missouri River and the large coal fields and power plants of the Powder River Basin of Wyoming make it one of the points where the two national power grids connect with each other, allowing switching of electrical power from east to west and vice versa.

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