21SL55

21SL55 is a precontact Native American archaeological site in the Boundary Waters of northern Minnesota, United States.

Artifacts documented at the site consist of ceramics, stone tools including a hammerstone, lithic debitage, and animal bones.

[3] As of the site's 1988 National Register nomination, only 2.5% of its area had been excavated, and no radiocarbon or thermoluminescence dating had been conducted, so its dating to the late Woodland period derived only from the surface treatment of the ceramic sherds, a projectile point, and the suggestion of intensive wild rice use.

[3] It is uncertain whether Blackduck people occupied 21SL55 seasonally or year-round, but the thick cultural layer suggests use over many years.

21SL55's location emphasizes that even very small islands played a role in the region's pattern of human settlement.