On a map of the Maryland coast, the change is clear: the Ocean City beach and Assateague beach no longer look the same as they did in the past. The sandbar that once ran straight now bends toward the west. This transformation is due to stone jetties built in the 1930s, which have caused the northern end of Assateague Island to move nearly 700 meters toward the mainland, according to NASA. The Ocean City jetties, built in 1933, blocked the natural flow of sand to Assateague Island. Over 70 years, the northern end of Assateague has receded nearly 700 meters toward the bay. To address this, the North End Restoration Project, launched in 2002, added 1.4 million cubic meters of sand in several phases to the beach. A breach caused by a storm in 1933 created a pass south of Ocean City, separating Assateague Island from the southern end of Fenwick Island. Normally, this gap would have filled over time as the longshore current carries sand from north to south. Ocean City was already becoming a popular beach resort before the storm. Between 1933 and 1935, a permanent jetty system was built to keep the pass open as a navigation channel. NASA dates the completion of the jetties to 1935 and notes that the structures were meant to help boats travel between the ocean and the bay. The Maryland Geological Survey dates the construction to 1934–1935. While local fishing prospered, the sand was blocked at the pass. The current’s direction didn’t change, but it now met an obstacle. North of the jetty, sand built up, widening the Ocean City beach, while Assateague Island no longer received sand, as noted in a USGS publication. The effects of the pass were initially overlooked, NASA acknowledges. But as the northern end of Assateague, now thinner, receded toward the bay—nearly 700 meters according to NASA, more than 500 meters according to another USGS publication, and nearly 1 km over 70 years, according to a vulnerability assessment—the changes became impossible to ignore. These differences stem from the time periods and sources used. Today, the two areas are separated by more than 1 km. A report by the U.S. Army Corps of Engineers on the southern jetty provides a sense of the rate of change. The northern end of Assateague is estimated to have receded about 35 feet per year, or 10 meters. Eventually, erosion reached the inner part of the jetty itself, which was repaired in 1956 using about 845 tons of stone. Concern over the island's rapid decline led to the North End Restoration Project. Its first phase, completed in 2002, added 1.4 million cubic meters of sand in one go—equivalent to about 560 Olympic pools, each holding 2,500 cubic meters. The project, designed to last 25 years, involved the National Park Service, the Corps of Engineers, and the Minerals Management Service. Sand is mechanically dredged and placed on Assateague beaches in stages to mimic natural processes. The USGS contributed to the effort through its research, and its November 2002 bulletin referred to "70 years of erosion due to the jetties." If the project is successful, it could serve as a model for other areas where human-made structures have disrupted sand movement. However, the project has its limits. Barrier islands naturally move toward the mainland as storm waves push sand toward the bay, a process accelerated by rising sea levels. The Ocean City jetties did not create this movement but intensified it at the northern end, where erosion has nearly doubled, averaging 2.9 meters per year, according to a study cited on ResearchGate. Ocean City did not benefit entirely, either. According to the Maryland Geological Survey, the groynes placed on its beach to hold sand in place have also disrupted natural drainage, worsening the island's recession. Eventually, the Corps of Engineers studied the feasibility of beach replenishment for the resort itself, with a report dated 1980.