Unsuccessful in Toronto, he left his wife and young children there and emigrated to British Columbia in the spring of 1859 via the Panama Railway and San Francisco in 3rd class steerage.
On his return journeys, he became entrusted with shipments of gold dust, and managed to reliably and safely convey earnings from the goldfields to Yale despite the ever-present risk of robbery, in addition to the difficulties posed by distance, climate, and the difficult canyon and plateau trails.
With the completion of the first section of the Old Cariboo Road to Soda Creek in 1862, Barnard used his own acquired capital and found a backer to launch Barnard's Express and Stage Line with fourteen six-horse coaches and a famous team of "crack whips" to drive them, including legendary drivers Steve Tingley and Billy Ballou.
The onset of the busiest phase of movement of miners and goods to and from the Cariboo Gold Rush began that year, and Barnard's new company prospered from a buys trade in services for passengers, freight, letters, newspapers and gold dust, and in 1864 was able to expand his business further with the purchase of more rolling stock and also in winning the government contract to carry the mail.
This proved to be disastrous, as the government's plans were ill-conceived, changing the route twice, and Barnard was forced to sit on a large investment in steamboats, packtrains, supplies, wire and other supplies until 1874, when a new government (that of A.C. Elliott) cancelled the contract altogether, as its predecessor had commissioned the clearing of a right-of-way for telegraph and railway before even confirming the route.
Barnard pursued a large claim for compensation, but the strain to his health from the losses incurred in this venture and the previous road-steamers misadventure contributed to a failing constitution.
Barnard, along with others such as John Robson, Hugh Nelson and Dr. Carrall, is considered to have been a "prime mover and father of confederation" in British Columbia, campaigning in the legislature and "on the stump".
Nevertheless, he resigned just before Confederation for British Columbia was achieved due to the circumstances of a private members' bill he wished to see pass.