{"id":18757,"date":"2026-11-04T00:50:45","date_gmt":"2026-11-04T00:50:45","guid":{"rendered":"https:\/\/wildgreenquest.com\/?p=18757"},"modified":"2026-11-04T00:50:45","modified_gmt":"2026-11-04T00:50:45","slug":"explosives-found-at-glen-canyon-and-antietam-park-sites","status":"publish","type":"post","link":"https:\/\/wildgreenquest.com\/?p=18757","title":{"rendered":"Explosives Found at Glen Canyon and Antietam Park Sites"},"content":{"rendered":"<p><br \/>\n<\/p>\n<div>\n<div class=\"justify-start\">\n<nav class=\"align-left col-span-full mb-base\" data-pom-e2e-test-id=\"breadcrumbs\"\/>\n<p>Discoveries of 1950s dam-blasting cord in Arizona and Civil War artillery in Maryland forced closures across two National Park Service locations, highlighting the unexpected hazards left behind in historic landscapes.<\/p>\n<\/div>\n<p><!--$?--><template id=\"B:1\"\/><!--\/$--><\/p>\n<div><\/p>\n<p class=\"fp-leadCaption py-tight text-left font-utility text-utility3-size leading-utility3-line-height text-secondary\">Glen Canyon Dam rises above the Colorado River near Page, Arizona. The National Park Service temporarily closed nearby Chains Road and The Chains day-use area after workers discovered detonation cord dating to the dam&#8217;s original construction in the 1950s and 1960s.<!-- --> (Photo: Gabe Ginsberg\/Getty)<\/p>\n<\/div>\n<\/div>\n<div>\n<div class=\"article-body\">\n<p>Published November 3, 2026 05:32PM<\/p>\n<\/div>\n<p>In a span of days, federal officials had to deal with explosives that were found at National Park Service sites on opposite sides of the country.<\/p>\n<p>On Oct. 30, the National Park Service announced in a <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/parkalerts.org\/node\/189\">public alert<\/a> that workers had discovered detonation cord near Glen Canyon Dam in Arizona, temporarily closing a recreation area at Lake Powell. The release said the cord was likely left over from the dam\u2019s construction in the fifties or sixties.<\/p>\n<p>That closure came shortly after an Oct. 21 <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/anti\/learn\/news\/antietam-visitors-should-plan-for-partial-closures-oct-27-28.htm\">announcement<\/a> from officials at Maryland\u2019s Antietam National Battlefield, where Marine Corps technicians removed unexploded Civil War-era cannonballs that were embedded in the monument\u2019s concrete base.<\/p>\n<figure id=\"attachment_2760429\" class=\"pom-image-wrap photo-alignnone\"><img loading=\"lazy\" alt=\"Glen Canyon Dam stretches across a red sandstone canyon in Arizona, with an arched steel bridge, electrical transmission towers and cloudy skies above it.\" loading=\"lazy\" width=\"2386\" height=\"1304\" decoding=\"async\" data-nimg=\"1\" class=\"alignnone size-full wp-image-2760429\" style=\"color:transparent\" srcset=\"https:\/\/cdn.outsideonline.com\/wp-content\/uploads\/2026\/11\/glen-dam-explosives_h.jpeg?width=3840&amp;auto=webp&amp;quality=75&amp;fit=cover 1x\" src=\"https:\/\/cdn.outsideonline.com\/wp-content\/uploads\/2026\/11\/glen-dam-explosives_h.jpeg?width=3840&amp;auto=webp&amp;quality=75&amp;fit=cover\"\/><figcaption class=\"pom-caption\"><span class=\"article__caption\">Glen Canyon Dam rises above the Colorado River near Page, Arizona. The National Park Service temporarily closed nearby Chains Road and The Chains day-use area after workers discovered detonation cord dating to the dam\u2019s original construction in the 1950s and 1960s.<\/span> (Photo: Gabe Ginsberg\/Getty)<\/figcaption><\/figure>\n<p>While incidents like these are rare, the Park Service has developed procedures for dealing with the discoveries of unexploded munitions or construction explosives. In\u00a02022, the agency began reviewing museum collections for potentially explosive ammunition, according to information officials provided to <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.aol.com\/articles\/part-antietam-national-battlefield-close-090957000.html\"><em>The Herald-Mail<\/em><\/a>. That same year, NPS published <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/subjects\/museums\/upload\/MHI_AppG_FirearmsAmmoMunitionsArtillery.pdf\">guidance<\/a> for handling historic munitions, followed by additional <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/home.nps.gov\/articles\/000\/archeology-egram-2023-01.htm\">safety procedures<\/a> in 2023 after an investigation involving the transportation of a live 19th-century cannonball from Fort Larned.<\/p>\n<h2>Forgotten in the Boreholes<\/h2>\n<p>Workers found several boreholes containing detonation cord along a restricted service road near Glen Canyon Dam, outside Page, Arizona. The cord is a flexible line filled with high explosives used to initiate blasting charges, according to the <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nist.gov\/glossary-term\/37946\">National Institute of Standards and Technology<\/a>.<\/p>\n<p>An explosive ordnance disposal team traced the material to the dam\u2019s original construction in the 1950s and 1960s. Officials said there was no threat to public safety and the dam faced low risk, but closed Chains Road and The Chains day-use area while evaluating mitigation options.<\/p>\n<p>The closure restricts access to a popular shoreline spot for swimming, fishing and picnicking, though the wider national recreation area remains open.<\/p>\n<h2>A Blast From the Past<\/h2>\n<p>The discovery points back to one of the most ambitious engineering projects in the American West. Construction on the 710-foot-tall Glen Canyon Dam began in 1956, requiring crews to blast diversion tunnels through sandstone canyon walls and excavate foundations down to bedrock.<\/p>\n<p>The project began with a dramatic display of patriotic pyrotechnics on Oct. 15, 1956, when President Dwight D. Eisenhower pressed a telegraph key in Washington, D.C., remotely triggering the first dynamite blast at the site, according to the <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.usbr.gov\/uc\/rm\/crsp\/gc\/\">Bureau of Reclamation<\/a>.<\/p>\n<p>Nearly 70 years later, the newly discovered detonation cord has brought explosives specialists back to the area, although officials have not linked it to Eisenhower\u2019s ceremonial blast.<\/p>\n<h2>Another Park, Another Set of Explosives<\/h2>\n<p>Roughly 2,000 miles east, at Antietam National Battlefield in Sharpsburg, Maryland, the Park Service faced historic ammunition of a different sort. On Oct. 21, park officials issued a <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/anti\/learn\/news\/antietam-visitors-should-plan-for-partial-closures-oct-27-28.htm\">press release<\/a> detailing plans to remove ten pieces of cannon ammunition set into the concrete base of the battlefield\u2019s O.T. Reilly Monument. Fought on September 17, 1862, the Battle of Antietam was the bloodiest single-day battle of the American Civil War.<\/p>\n<figure id=\"attachment_2760430\" class=\"pom-image-wrap photo-alignnone\"><img loading=\"lazy\" alt=\"A rectangular stone memorial with an engraved inscription stands on a concrete base at Antietam National Battlefield in Maryland. Several dark, rounded artillery projectiles protrude from the concrete surrounding the monument, with green grass and leafy trees in the background.\" loading=\"lazy\" width=\"2400\" height=\"1889\" decoding=\"async\" data-nimg=\"1\" class=\"alignnone size-full wp-image-2760430\" style=\"color:transparent\" srcset=\"https:\/\/cdn.outsideonline.com\/wp-content\/uploads\/2026\/11\/antietam-explosives-removed_h.jpg?width=3840&amp;auto=webp&amp;quality=75&amp;fit=cover 1x\" src=\"https:\/\/cdn.outsideonline.com\/wp-content\/uploads\/2026\/11\/antietam-explosives-removed_h.jpg?width=3840&amp;auto=webp&amp;quality=75&amp;fit=cover\"\/><figcaption class=\"pom-caption\"><span class=\"article__caption\">The O.T. Reilly Monument at Antietam National Battlefield in Maryland \u00a0features a concrete base embedded with 10 pieces of historic artillery ammunition, prompting the National Park Service to arrange for their removal in October 2026. <\/span> (Photo: NPS Antietam)<\/figcaption><\/figure>\n<p>A team of Marine Corps explosive ordnance disposal specialists from Quantico, Virginia, was scheduled to handle the extraction on Oct. 27 and possibly Oct. 28. Because the ammunition might still contain explosives, officials planned to close the visitor center, historic Dunker Church, adjacent roads and two walking trails, keeping the operation closed to public viewing.<\/p>\n<h2>Monumentally Questionable Building Materials<\/h2>\n<p>The monument\u2019s unusual masonry was the work of Oliver T. Reilly, a local figure who witnessed the Battle of Antietam as a boy in 1862. He spent his adulthood in Sharpsburg, Maryland, working as a battlefield guide, local historian, and collector, according to a <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/anti\/learn\/historyculture\/mnt-reilly.htm\">historical profile<\/a> from the National Park Service.<\/p>\n<p>Reilly dedicated his monument in 1927, honoring the Dunker Church, a historic oak tree and local Union Army veterans, the profile said. He embedded 10 artillery projectiles from his private collection into the concrete base, giving a place of worship, an old tree and retired servicemen a rather unexpected amount of firepower.<\/p>\n<p>Antietam isn\u2019t the first park to contend with potentially explosive remnants of its military past. A Civil War-era cannonball interrupted tours at <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/fosu\/learn\/news\/historic-ordnance-discovered-at-fort-sumter.htm\">Fort Sumter<\/a> in 2022, while another discovered at <a rel=\"nofollow\" target=\"_blank\" class=\"article-content-link text-brand-primary underline hover:text-brand-primary\/85 break-words overflow-wrap-anywhere underline-offset-[3px]\" data-afl-p=\"0\" href=\"https:\/\/www.nps.gov\/fomc\/learn\/news\/historic-ordnance-discovered-during-excavation.htm\">Fort McHenry<\/a> in 2025 prompted an evacuation before technicians determined it was inert.<\/p>\n<p>At Antietam, officials planned to transport the ammunition to Quantico and return Reilly\u2019s monument to a rebuilt base. At Glen Canyon, no reopening date has been announced for The Chains, leaving a former construction staging ground closed to the people who now come there to swim.<\/p>\n<p><span hidden=\"\" aria-hidden=\"true\"\/><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/www.outsideonline.com\/outdoor-adventure\/environment\/explosives-found-national-park-sites-glen-canyon-antietam\/\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Discoveries of 1950s dam-blasting cord in Arizona and Civil War artillery in Maryland forced closures across two National Park Service locations, highlighting the unexpected hazards left behind in historic landscapes. Glen Canyon Dam rises above the Colorado River near Page, Arizona. The National Park Service temporarily closed nearby Chains Road and The Chains day-use area<\/p>\n","protected":false},"author":1,"featured_media":18758,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-18757","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wild-living"],"_links":{"self":[{"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/posts\/18757","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=18757"}],"version-history":[{"count":0,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/posts\/18757\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=\/wp\/v2\/media\/18758"}],"wp:attachment":[{"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=18757"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=18757"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wildgreenquest.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=18757"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}