The world’s tallest active geyser, Steamboat, erupts in this file photo from May 23, 2005, in Yellowstone National Park. The geyser has recently become active again, erupting a number of times this year. (WikiCommons)

CASPER, Wyo. — A Washington man got a seven-day jail sentence and a two-year ban from Yellowstone National Park for going off the boardwalk and coming within 20 feet of Steamboat Geyser’s steam vent, according to a release Thursday by the U.S. Justice Department.

“Trespassing in closed, thermal areas of Yellowstone National Park is dangerous and harms the natural resource,” said Acting United States Attorney Eric Heimann in the release. “In cases like this one where we have strong evidence showing a person has willfully disregarded signs and entered a closed, thermal area, federal prosecutors will seek significant penalties, including jail time.”

21-year-old Viktor Pyshniuk, of Lynwood, Washington, was sentenced on the thermal Trespass charge June 4 by Magistrate Judge Stephanie A. Hambrick,

A park employee got a photo of Pyshniuk, “who had clearly crossed over the fence and was walking up the hillside,” the release said. A park law enforcement officer contacted Pyshniuk and showed him the numerous posted signs saying it is illegal to leave the boardwalk.

Weak ground layers, mud pots and heated steam and water are some of the many dangers associated with the unpredictable geothermal area, the officer said. Steamboat Geyser, the world’s tallest active geyser, is also the most dangerous, according to the release.

“It has erratic and unpredictable eruptions that can rise anywhere from six to 300 feet high. In the last four years, the intervals between eruptions ranged anywhere from three to 89 days according to the YNP website,” the release said.

Hambrick explained to Psyniuk that the sentence was designed to deter him and others from leaving the boardwalks. She noted that Psyniuk’s actions were seen by the people around him who might have thought it was OK to do the same.

“And if every visitor to YNP disobeyed the rules, the park would be destroyed, and no one would be able to enjoy it,” she said in the release.

Hambrick also explained that the 3-foot fencing around the boardwalk is a clear sign that the area is closed and prohibited from entering.