Long before giant ice sheets carved out our modern landscape, the ground beneath our feet was an unpredictable region of violent continental rifts, raging rivers of lava, and an almost endless inland sea. Get our free mobile appCredit: Canva Credit: CanvaDid you know Minnesota used to be in the tropics? Sea levels were much higher around this time, which is why much of Minnesota was covered with a vast inland sea. These days, you can still find evidence of the inland sea in the towering limestone bluffs along the Mississippi River, along with the St. Peter Sandstone hidden right beneath the Twin Cities Metro. You can check it out for yourself by visiting the Morton Outcrops Scientific and Natural Area, on the west side of Morton, Minnesota.