The fourth man involved in trespassing and damaging the Grand Prismatic Spring in Yellowstone National Park was identified in federal criminal complaint unsealed on Monday.

Hamish McNab Campbell Cross was charged with the same two crimes as his three companions with the Vancouver, B.C.-based clothing company High on Life SundayFundayz when they left the boardwalk and walked on the delicate bacterial mat of the spring on May 14, according to court records.

The three -- Charles Ryker Gamble, Alexey Andriyovych Lyakh and Justis Cooper Price-Brown -- were identified in the original criminal complaint and arrest warrants filed on Monday, May 17. They were charged with violating a regulation that requires people to stay on designated board walks or trails, and with creating or maintaining “a hazardous or physically offensive condition.”

According to the criminal complaint written by ranger Alec Chapman, a park visitor on May 15 gave him photos and a video taken of the four men on the spring near Mammoth on May 14. The visitor also provided photos of High on Life's blue recreational vehicle with a British Columbia plate. From that evidence, Chapman determined it was registered to Gamble, the company's chief management officer.

The SundayFundayz Facebook page showed pictures of the three, which were later deleted. However, people took screen shots of those pages and reposted them to the Facebook page.

Chapman was able to identify Cross through other photos and determined he entered the United States on a New Zealand passport.

Cross was charged on Thursday, and the complaint was unsealed by U.S. Magistrate Judge Mark Carman on Monday.

The alleged crimes are misdemeanors, punishable by up to six months in jail and $5,000 fines.

Wyoming U.S. Attorney spokesman John Powell said last week the federal government will not seek extradition of them because the crimes are misdemeanors.

However, traditional and social media have reacted with outrage, because the four men have reported themselves acting unethically or illegally at other places in the United States, Peru and Germany.

High on Life did not respond to a Facebook message seeking comment last week.