ASSATEAGUE — Last week’s discovery and planned detonation of over 100 pieces of World War II era military ordnance on Assateague, and the subsequent clean sweep conducted by the Army Corps of Engineers last weekend, recalled the once-remote barrier island’s rich history as wartime military test range and its genesis into a national park visited by hundreds of thousands each year.

Decades-old unexploded ordnance was discovered on the North Ocean Beach section of the Assateague Island National Seashore and was later assembled and detonated in several planned explosions by Army teams from Aberdeen. The Ocean City Bomb Squad initially determined the size, scale and type of munitions discovered on the beach were beyond its capabilities and the Emergency Ordnance Disposal (EOD) team from Aberdeen Proving Ground was brought in.

Last Friday, the Army Corps of Engineers arrived on Assateague and completed a two-day thorough sweep of the island using sophisticated instruments and gave the okay on Saturday afternoon to open the areas closed to the public in the days following the discovery last Monday. With the decision to open the closed areas came the caveat the island is in a constant state of flux and more ordnance can, and likely will, be exposed in the future.

According to a Defense Environmental Restoration Program report prepared in 1994, Assateague saw its share of wartime activity during both world wars. During World War I, the first successful German U-boat attack in U.S. coastal waters occurred just 30 miles southeast of Tom’s Cove and the last ship sent down at the end of the war in 1918 was sunk just 10 miles from Assateague. During World War II, several vessels were torpedoed and sunk within sight of Assateague. The U.S. Coast Guard manned stations on all of the barrier islands in the mid-Atlantic region during World War II including Assateague and the island was used for quarantine purposes and “special training.”

However, it was during World War II and for a few years beyond the end of the war when Assateague was used most extensively as a test range by the Navy and the Army Air Corps for a variety or weapons and munitions. It was during those years from 1943 to 1947 that much of the old ordnance still discovered from time to time, including the large cache found and detonated last week, was deposited in and around Assateague.

In 1988, Army and Navy EOD teams were deployed to Assateague Island at the request of the National Park Service when ordnance items washed ashore at the North Ocean Beach in July. The North Ocean Beach area is believed to coincide with the Stinger rocket ranges used for testing during World War II.

The EOD teams in July 1988 recovered and disposed of three five-inch rockets with at least one containing a rocket motor. The following day, the EOD team returned to the site to recover and dispose of another five-inch rocket that washed ashore in the same area. According to the report, it appeared at the time that the ordnance was coming from a hole roughly 15 yards offshore.

From July 17-20 in 1988, the U.S Navy EOD Mobile Unit conducted an underwater survey of the area around the hole. The results of that survey led Navy EOD leaders to believe the hole was actually a trench dug to bury expended shells and other munitions found while clearing the range. It was also believed that the trench was originally on Assateague Island, but was now underwater due to the island’s natural migration.

The ordnance recovered by the EOD teams included seven rocket motors, one of which was not expended; six five-inch shells, two of which were live; and numerous ballistic tips used to improve the aerodynamics of practice rockets. According to the report, no removal action was taken on the majority of the suspected ordnance at that time.

In 1991, a preliminary assessment of Assateague Island was conducted under the Defense Environmental Restoration Program for Formerly Used Defense Sites. The preliminary assessment found Assateague had been used by the War Department. The War Department’s use of Assateague Island during the war was substantiated by a former Navy spotter and, of course, by the actual ordnance washing ashore in 1988.

In 1991, the Army Corps of Engineers subcontracted a private firm to conduct a preliminary assessment on Assateague. The focus of that assessment was to determine the location of the Stinger rocket range and its accompanying burial trench. Further research revealed Assateague Island was used as a rocket, bombing and strafing range in support to Air Station Chincoteague and Air Station Manteo in North Carolina during the war.

As a result of its findings, the private firm recommended a large-scale sweep of the island with particular attention on the North Ocean Beach area. The sweep was conducted from February to March 1992 and over the three-week period, 436 lanes and over 570,000 square feet of beach were searched. The investigation focused on the 17,552 acres of Assateague believed to have contained two rocket ranges known as Stinger One and Stinger Two, and two accompanying burial trenches used by the Navy and possibly the Army Air Corps.

During the extensive sweep, some unexploded ordnance was discovered and disposed of, although the resulting report warned the more ordnance could be uncovered in the future because of the barrier island’s ever changing shoreline and landscape.

In the years since, Assateague has been classified by the Army Corps of Engineers as a formerly used defense site. A Military Munitions Response Program Site Inspection was completed in 2007 and the site inspection recommended that a Remedial Investigation and Feasibility Study be performed in the future. However, due to funding limitations and the prioritization of activities ongoing at other sites, the remedial investigation and feasibility study for Assateague has been pushed back to 2020.

According to an archeological overview and assessment of the maritime resources on Assateague Island prepared by the Maryland Historical Society in 2002, a site visit was made in July 1991 and determined that while the southern end of the island was relatively stable, the erosion of the northern section is moving the ordnance, which was buried at the high water mark in the 1940s offshore and under the swimming area.

“Because of the hazard to public safety, the Corps recommended a large-scale sweep of the area using ground penetrating radar and electric pulse induction equipment to locate and remove the five-inch shells with lead alloy ballistic tips,” the report reads. “This was done in 1992, but ordnance continues to appear sporadically. Notes in the NPS files at Assateague Island National Seashore comment that the rockets only carried sufficient explosives to detonate a smoke bomb to show the results of the tests, but the NPS prefers visitors not to find these.”