Frankly, you would be incredibly lucky and skilled, as an Anthropologist, to find 'a lot' of human remains in the same strata. To find 'a lot' of human remains in the same strata all the way down to 200,000 years ago would be nothing short of miraculous. The fact is that fossilization is an iffy business, and even if a bone does become fossilized it can be unburied due to erosion and basically erode away. That and the fact that we have no way to view what fossils remain in the geology underneath our feet over a large area, helps to keep many fossils hidden. That isn't to say that we don't have evidence of human activities that don't include bones. These can and do include such activities as lithics, butchered bones (ex. marrow extraction, cut marks, pot rub, discoloration, etc.), cultural remains (ex. artwork, homes, fire pits, jewelry, artifacts, etc). If you allow for the full range of fossils and human cultural remains then the breadth of evidence showing Homo Sapiens has been around for more than 100k years is overwhelming.