There are several cemetaries built around mounds, but this is the first time I've heard of burials on top of mounds... I guess we found the decendants of the original Intrusive Mound Culture.
I love seeing mounds, and some of the best preserved ones are indeed in cementaries.
Marrietta Ohio has a large mound in their cemetary which is famous because of the quantity of revolutionary war veterens buried there. There is another well known one in Romney West Virginia. There are a couple in Indiana, one in Tippecanoe County and one right off i-65 between Louisville and Indianapolis. And one in Racine Wisconsin, and a couple in Illinois that I haven't been to.