When viewed from the air, the Bighorn River cuts across the Sheep Mountain anticline. As Sheep Mountain is a topographic high and barrier to streamflow, how was the river able to establish itself and eventually erode through the anticline?
-The Ancestral Bighorn River established a course over the landscape while the anticline was still buried at depth.
-Rifting of the landscape created fractures for groundwater to follow, which eventually coalesced to create a river.
-A normal fault bisects Sheep Mountain, which created a path for water to flow.
-Uplift of mountains nearby diverted the river, which eventually wore a path through the anticline.
-Melting glaciers at the peak of Sheep Mountain created meltwater streams that eventually carved through the mountain.