rest of Iowa, the Paleozoic Plateau was bypassed by the last of the Pleistocene glaciers (the Wisconsin), allowing the region's fast cutting streams to expose and carve out deep channels in the bedrock-dominated terrain. The area is characterized by thin loess soil cover, isolated patches of glacial drift, deeply entrenched river valleys, and karst (sinkholes, caves, and springs) topography. Conservation issues From 1999 to 2009, Superintendent Phyllis Ewing "oversaw more than $3 million in illegal construction of boardwalks, trails and other structures that damaged irreplaceable archaeological artifacts." She failed to conduct consultation with affiliated American Indian tribes and follow procedures of the National Historic Preservation Act and other statutes. The Park Service conducted an internal investigation, finding numerous violations but no intent to damage the park. In July 2016, Thomas Munson, Superintendent for 20 years of the Effigy Mounds National Monument, was sentenced to several days in prison after pleading guilty to stealing bones in 1990 of 40 ancient Native Americans, who lived between 700 and 2,500 years ago, from the holdings of the museum at the site. The remains had been excavated along with artifacts from burial mounds at the park. Munson was apparently trying to evade the proposed provisions of the Native American Graves Protection and Repatriation Act (NAGPRA), which was passed by Congress that year. The act provides for artifacts and bones to be returned or repatriated by governmental agencies and other institutions to tribes who are affiliated with the peoples who buried the items. Tracing the bones could have demonstrated a link to the affiliated tribes and required return of both the remains and related artifacts from grave goods. Without that evidence, most of the artifacts have been retained by the park museum. The government conducted a five-year investigation through the US Attorney's Office, following questions raised in 2011 by Iowa Tribe of Kansas and Nebraska member Patt Murphy. As tribal representative under NAGPRA to receive "remains and funerary objects for repatriation and reburial," he had requested an inventory from the national monument of all remains and goods, which they could not provide. This began the inquiry. Murphy has praised the work of the US Attorney's Office and others in this case. Munson was sentenced to a year of home detention, 10 weekends in jail, and paying "$108,905 in restitution for the damage he caused to the bones and a $3,000 fine." Munson had retired from