I don't believe that red jasper is common to my area, i am in southern New Jersey, sort of part of the coastal plain and in the Pine Barrens. It is very sandy here, at some point this was ocean.
Lucky for me, my mom has one of those cottage country gardens, not very formal, so the place where I wrenched this out did not suffer much! I had been eyeing it for some time, years really, wondering why there was reddish rock in a mostly slate and some quartz wall...and by the way, the stones are mostly flat in shape, stacked on top of each other, not cemented together - so it was easy to get it out. I just had to remove some of the top stones first.
In talking to my mom, who also has no idea from whence the red jasper came, we were thinking one of my brothers may be able to solve the mystery - he always had snakes and lizards and other such critters, possibly he purchased this stone at some point for an aquarium interior decorating theme. When the aquarium was dismantled, perhaps the stone found it's way out to the yard and eventually was put onto or into the wall. The reason I am thinking this is because there are also some pieces of petrified wood in my mom's garden, and those came from my brother's old iguana habitat.
Another hypothesis - the original owner of this home was from the western states, where I believe jasper IS common - and he also was the owner of a big landscaping and pond company. So possibly he had the stone as part of the garden decor.
I hesitate to ask my brother - what if he says "Oh WOW you found my prized piece of red jasper! Thanks Jen!!" (grabs red jasper right out of my hands) So, maybe it is best to just keep it a mystery....that is, till the inevitable day when said brother comes for dinner and is looking around my house....