It’s unclear if the coins were accidentally or intentionally dropped by a Lake Powell visitor, Plumb said. A Colorado hiker discovered them near the Halls Crossing Marina and turned them over to National Park Service rangers.
It sparked an investigation into whether the coins were a hoax or had been dropped by someone during the famed 1776 Dominguez and Escalante Expedition led by Spanish priests Father Atanasio Dominguez and Father Silvestre Velez de Escalante.
The National Park Service brought in Spanish coin experts Dr. Fernando Vela Cossio and Luis Fernando Abril Urmente to assist in the investigation. According to Plumb, they concluded the coins presence near Halls Crossing is modern based on three observations:
First, the dates of the two coins are widely divergent (1252-1284 and 1662-1664) and are significantly earlier than the Dominguez and Escalante Expedition, the first known Spanish presence in the area.
Second, the coins were found in a scatter of modern houseboat trash that included 15 United States coins dating from 1974 to 2016.
Third, the coins were found in a canyon bottom, a setting unlikely to preserve ancient deposits. The lack of nearby places having potential to contain ancient deposits suggests the coins are not associated with 17th or 18th century Native Americans or Spanish explorers.
“The coins do tell two important stories,” Plumb said. “First, the visitor who found the coins and turned them into the park showed great respect for the history and resources in the park, and instead of keeping them, ensured everyone could learn about the coins.
“Second, the coins’ exact location and what they were found with has contributed to educated guesses about their history. This is why archeological artifacts should be left in place and reported to the land management agency. Where they are is just as important as what they are.”