Spending high school summers at Lake Arrowhead working on boat docks, running boat motors, and diving for engines, North Hollywood, California, native Dick “Mac” McCallum watched a travel adventure film featuring Georgie White.  Just out of high school in 1957, 17-year-old Mac went with Georgie on his first Grand Canyon river trip as a paying passenger.  In the lower end of the Canyon, one of the boatmen on the triple rig “thrill boat” hiked out.  Georgie had noticed Mac as a great replacement and at that point he became a Grand Canyon boatman. Mac also accompanied Georgie as crew through Glen Canyon, Cataract Canyon, the Middle Fork and Main Salmon Rivers, Alaska, and Mexico.

In the early 1960s, Ron Smith, another Georgie passenger, became a main boatman along with Mac. They built rowing decked canoes to run the Green and Colorado Rivers from the Green’s headwater to document the undammed stretches, a trip which ended part-way through Grand Canyon. Discussion on that trip resulted in them co-founding Grand Canyon Expeditions (GCE) in 1964. In 1966, Mac conducted his first Outward Bound-type youth trip through GCE in Grand Canyon. Going into teaching and counseling careers, Mac felt that experiential education with youth was a more than worthy goal for both them and him. In 1970, he and wife Susie founded Grand Canyon Youth Expeditions (GCYE) to do just that. Mac designed a galley-rowing style boat, using two military surplus bridge pontoon “snouts,” with a frame between. This allowed participation for four rowers, and a boatman at the stern with a steering oar. Participants took turns guiding the rigs and also coordinated with all camp chores. That rig became the basis for a one-rower snout rig that some Grand Canyon outfitters adopted. Mac also adapted it for a motor rig with double snouts, and his original rig may have influenced the evolution of smaller catarafts, popular with private boaters.