Daniel Greenhalgh was found guilty of breach of trust and sexual assault in October 2010.
He was sentenced to two years in prison, followed by three years of probation.
Greenhalgh appealed, seeking nine months in prison and arguing the judge's sentence was unlike those handed out for similar offences.
B.C.'s Court of Appeal ruled, however, that Greenhalgh couldn't demonstrate the sentence is unfit and said there is no basis to interfere with the judge's ruling.
During the original trial, the victims testified Greenhalgh took them to secluded areas at the border crossing and conducted strip searches.