The three defendants entered their pleas during a hearing before U.S. Magistrate Judge Mark Carman at the Yellowstone Justice Center in Mammoth Hot Springs on Thursday.
Four of the High on Life group were originally charged with disorderly conduct by creating a hazardous condition and foot travel in a thermal area in Yellowstone.
The Assistant U.S. Attorney said he would like to have all the cases resolved as one, but that may not be possible. The next status conference with the court is Aug. 8.