Pretty sure that is a typical North American stone axe head. They were made by the millions over the millenium (from 13,000BC until the advent of the steel trade tomahawk). They are a common artifact all over North America where streams and glaciers provide stones the right size and shape to easily convert into a axe. North American axe heads are somewhat of a misnomer as they were often not sharp enough to chop wood with. They were used to crush bark, break open bones, fight, and basically do what people do with hammers and hatchets today. More carefully crafted, sharp stone heads are much more rare than these rough utility models. Stone axes with a hole for a handle are rarer still in North America and are most often found in Europe. Often these rough ones were easy enough to make that they would take them and lay them up in the forks of small trees and leave them there for years and allow the tree to grow around it, making a very tight fit. More often, wood was bent around to form a crude haft.