Roberts founded the first trekking and mountaineering outfit Mountain Travel Nepal in 1964 to offer the opportunity for wealthy travellers to enjoy the experience of trekking or climbing in Nepal without problems. His trained Gurkha/Sherpa teams, took care of transportation, camping and local liaison, leaving trekkers free to enjoy the thrills. The first trek he managed was one by three elderly ladies to Everest Base Camp in 1965. He is known and revered as the father of trekking in Nepal.