make arrests with a warrant or process for misdemeanor violations, or without a warrant or process for violations of such misdemeanors that any such officer or employee has probable cause to believe are being committed in his presence or view, or for a felony with a warrant or without a warrant if he has probable cause to believe that the person to be arrested has committed or is committing such felony, for offenses committed within the National Forest System or which affect the administration of the National Forest System;;