OOC: Cave location is around 38.698037,-92.295799 and the shining metal was on the other side of the river, with no obvious safe way to get across at the moment.
As Alicia consults the map on her Pip Boy, she can see that there's what used to be a small boat ramp on the river three miles to the west, following the river. There was also the main bridge going into the state capital that's 16 miles away to the east. Other than the former state capital, the closest town is 10 miles away to the north.