The recent discovery of two ancient Spanish coins near Halls Crossing excited archaeologists at Glen Canyon National Recreation Area, who wondered whether they offered evidence that Spanish explorers, possibly in search of mythical cities of gold, passed through Utah centuries ago.

While the coins were determined to be authentic, National Park Service officials have now concluded that they were not left behind by Spaniards in colonial times. Circumstantial evidence, such as the 400-year difference in the two coins’ ages, indicates they most likely came from a modern collection, but that finding raises other questions.

Why would someone just throw away or lose valuable coins, dating back to the 13th and 17th centuries, in Utah canyon country? Yet the coins do tell two important stories.

“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,” the park service wrote in a news release Tuesday. “Second, the coins’ exact location and what they were found with has contributed to educated guesses about their history. This is why archaeological artifacts should be left in place and reported to the land management agency; where they are is just as important as what they are.”

Not immediately appreciating their historic significance, a hiker picked up the coins late last year and then turned them into park officials after realizing they could be artifacts, according to a May 8 post on National Parks Traveler. The park service launched an archaeological inquiry, hiring Spanish coin experts Fernando Vela Cossio and Luis Fernando Abril Urmente to help with identification and scouring the spot where they were recovered.

The smaller of the two coins, called a dinero, was minted between 1252 and 1284, dating to the reign of Alfonso X. The larger coin is a “16 maravedis," dating from 1662 to 1664. The coins’ mintings, four centuries apart, date to at least a century before the famous expedition of Atanasio Domínguez and Silvestre Vélez de Escalante, who crossed southern Utah in 1776.

Some historians have speculated that Spanish explorers and soldiers had wandered into Utah long before the Franciscan priests, but little physical evidence has surfaced to support that. And these two coins, as tantalizing as they first appeared, offer no insights into that possibility.

The chances that a historic expedition was carrying coinage of such far-ranging vintages seemed remote but still possible. It was the context of the location, in a canyon bottom along with scattered houseboat trash, that shot down the possibility the coins were left centuries ago.

The moist environment on a canyon floor is not conducive to the long-term preservation of metallic objects. And investigators found plenty of modern objects at the site. Among the trash scattered there were 15 U.S. coins dating between 1974 and 2016.

“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 park service release states. The most plausible explanation is the Spanish coins were accidentally or intentionally dropped relatively recently.