Three Rivers Ranch Guide School – May 13th – 20th Three Rivers Ranch Guide School – May 13th – 20th TRRoutfitters2017-02-21T21:07:00+00:00 Three Rivers Ranch Guide School will be held May 13th to May 20th and will also be held in October. If you've Three Rivers Ranch Guide School – May 13th – 20thTRRoutfitters2017-02-21T21:07:00+00:00