A tourist has been fined US$1000 for collecting water from a hot spring in Yellowstone National Park.
The incident follows a recent death at the park, when another tourist fell into a hot spring in a restricted area.
Officials said that a Chinese tourist was caught walking off a boardwalk and collecting water in the Mammoth Hot Springs thermal area on Tuesday.
The man was also seen breaking through a surrounding travertine crust, a fragile limestone deposit generated by the spring.
After being interviewed, the tourist said he had not read the safety information provided at the park entrance. He also admitted to collecting water from the spring.
The tourist faces court charges and will make an appearance in the Yellowstone Justice Center Court.
"Park rangers appreciate the willingness of the witness to document and report the violation," officials said in a statement.
"Park employees call on all visitors to protect their park and protect themselves.
"Without visitor cooperation, park natural wonders will continue to be damaged and more individuals may be injured or killed. It is a violation of federal regulations to collect any park resources."
Last month, a baby bison had to be euthanised after well-meaning tourists became concerned for its safety and transported it to a ranger station in the back of their SUV.
Only days later, a group of Canadian YouTubers - including one New Zealander - were hit with criminal charges for walking on an off-limits geyser in the park.