I think the name for the hill is Tabor Mountain or the Ivory Tower. It is a good example of invert topography. Iron-rich muck formed in an old river bottom. The river dried up several million years ago as the iron-rich muck hardened into ironstone. Now the river bottom was harder than the old banks, which being softer eroded away. The softer banks wasted away while the the ground beneath the hard capped land remained intact. This is a subtle badlands landscape, where ironstone boulders slowly travel down slope as the ground beneath them wastes away, in large part during permafrost thaw events.
S-M