Maybe I missed the size and weight of the stone? But, was a genuine stone brought over by an enterprising immigrant and planted?
The Stone is 36"x18"x6", and of granite-like material. It could have come by train, wagon, travois or boat. It's not native to the Kensington area and came from a considerable distance. It would have been a lot of trouble to to transport by wagon or travois. Train would have been expensive for a joke. In 1898, there was no navigable lake.
Thus the enterprising immigrant would have needed time, 14th century runic knowledge, money, strength, a chisel, stone carving skill, patience and a warped sense of humor. Sound like any body you know?