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In page Gogo Falls:

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The 1989 excavations of this area were conducted by Karega-Munene. The excavation decided to focus on the area that was adjacent to the river. They established a grid that resulted in 52 squares, each measured 5m x 5m. There were two plots that produced the most finds and they were identified as Area A.[2]:59 After those plots provided so many finds they excavated more squares in that area which were labeled 1 through 30.[2]:59 The excavations of these squares were different than Robertshaw’s excavations because the topsoil was not removed by shovels, but instead separated into 10 cm spits.