Assigned to the 4th Naval District, Gallup carried out minesweeping duties into the early weeks of 1918.

At 1200 hours on 20 February 1918 Gallup, by then under the command of Ensign C. P. Berlin, USNRF, was anchored in the Harbor of Refuge at Lewes when a moderate northwest gale caused her to drag her anchor.

The following morning, despite the fact that her engines were working at full power, Gallup ran aground, stern first, on the point of Cape Henlopen, Delaware, swinging around broadside to the beach.

In response to her distress signals, United States Coast Guard crews from nearby lifesaving stations brought her complement ashore without loss of life.

However, Gallup broke in two forward of her engine room and was declared a total loss.