Not seeing where to place marker for spade gulch mission

[Jaco88laze]

When i 1st played the mission where you have to place a marker at spade gulch, the blue marker was there at the spot where I should place it. It was destroyed some how. The bug near by killed me and when I came back the blue marker showing me where to place the marker was gone. I placed a whole lot of markers in that spot and still... nothing is happening