The North Dakota monument of Washington, D.C.'s World War II memorial was vandalized with graffiti to protest the controversial Dakota Access Pipeline Project.
A teacher from Bismarck, North Dakota is in the nation's capital with a group of students and discovered the graffiti on Monday, MyNDNow.com reported.
Kristi Heupel, a resident of Bismarck, posted on Facebook a picture of the vandalism, which appears to read "#NoDAPL," a reference to the disputed Dakota Access Pipeline.
The pipeline has garnered national attention after large-scale protests have tried to stop its construction. The protests have largely been led by local Native American groups that allege the pipeline, if completed, will run through sacred lands and contaminate water supplies in the area.
Supporters of the 1,170-mile pipeline, a $3.7 billion project that would transport 470,000 barrels of oil a day across four states, argue it will pour millions of dollars into local economies and provide thousands of jobs. Parties involved in the dispute disagree over the environmental safety of the project.
Heupel's Facebook post said the North Dakota section was the only part of the WWII monument that had graffiti. Pillars representing each U.S. state and territory from 1945 surround the memorial, honoring those Americans who served during the war as soldiers and civilians.