Pompeys Pillar National Monument is a rock formation in Yellowstone County, Montana designated in 2001 and managed by the BLM. It is one of the smallest national monuments in the United States at only 51 acres.
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Pompeys Pillar National Monument is a rock formation in Yellowstone County, Montana designated in 2001 and managed by the BLM. It is one of the smallest national monuments in the United States at only 51 acres.