Just my two cents, it looks like you're in an area that was once covered by glaciers. Most of the larger stones that you've posted have deep striations caused by glacial weathering. This happened when pebbles picked up by the glacier, some 10,000+ years ago, gouged along the stone's surface, leaving deep groves.
I will occasionally run into rocks like that in the stretch of woods that I hunt in Massachusetts. The main giveaway for these types of rocks is the fact that the grooves seem "gouged" horizontally into the stone rather than pecked, and there are often many grooves of varying depths on the same stone. They all run parallel in the same direction around the stone.
Glacial weathering will often reveal different stone "layers" in the groves. This is due to the mechanism of erosion, with the rock weathering off in layers. You typically don't see these layered grooves on Native American pecked stone axes.
The next time I see a similar rock, I'll send a picture in this thread. In the meantime, here's an example of glacial weathering that I found online. You can see that this example has the beginnings of groves forming. The major characteristics are a) many parallel groves and b) you can see the layers. If this process were to go on farther, it could produce larger, deeper groves or other interesting shapes.
Although they are not Native American, your finds are equally interesting in their own right. They bear testament to an incredible process by Mother Nature that is many thousands of years old. Hope this helps!
