A Yellowstone geyser made its largest eruption in about 60 years last month when it shot water about 30 feet into the air, the U.S. Geological Survey said last week.

The eruption, which occurred on Sept. 15, was the largest since 1957. Officials said aside from water the geyser also spewed years of trash buildup that had been left in the hot spring, the Yellowstone National Park wrote in a Facebook post.

“After Ear Spring erupted on September 15, employees found a strange assortment of items strewn across the landscape around its vent! Some are clearly historic: they'll be inventoried by curators and may end up in Yellowstone's archives,” the Facebook post read.

Park officials also warned visitors that leaving trash to fall into the spring could damage the geyser.

“Foreign objects can damage hot springs and geysers. The next time Ear Spring erupts we hope it's nothing but natural rocks and water. You can help by never throwing anything into Yellowstone's thermal features!”

Photos posted on the park’s Facebook page showed several coins, a pacifier and a cement block, among other items, the Miami Herald reported.

The eruption led to fears of volcanic activity below the geyser. However, the agency said there was no “signs of impending volcanic activity.”