Henry's mining career began with a telegram from his brother, Noah, that led to the pair buying into the La Rose silver claim in
Cobalt, Ontario, at the onset of the
Cobalt silver rush.
Fred La Rose, a
blacksmith, while working for brothers Duncan and
John McMartin in the construction of the
Temiskaming and Northern Ontario Railway (T&NO) at Mile 103 from
North Bay, Ontario– where he had built a small cabin –there chanced upon
Erythrite, often an indication of associated
cobalt and native
silver. (A fanciful story later developed that La Rose discovered the vein when he threw a hammer at a pesky fox.) Noah Timmins subsequently heard of the claim from La Rose who, at the end of his contract, had stopped at the Timmins brothers'
general store in Mattawa, while returning to his home in
Hull, Quebec. Noah
cabled Henry, who was in
Montreal at the time and immediately set out for Hull, where he met with La Rose and offered him $3,500 for a quarter share of the claim, effectively partnering with the McMartin brothers. The foursome soon added a friend of the Timmins brothers, attorney
David Alexander Dunlap (1863–1924)– for whom the
David Dunlap Observatory was named –as a full fifth partner, after he had won a case lodged by then former
Temiskaming and Northern Ontario Railway Commissioner
M.J. O'Brien, who had bought out adjacent claimant, Neal A. King, then disputed the Timmins' claim. In 1910, the five partners incorporated as the Canadian Mining and Finance Company, Limited (later
Hollinger Mines), with Noah appointed President. In 1916, officers of the corporation were reported as: "President, L. H. Timmins, Montreal; vice-president,
J. McMartin, Cornwall, Ont.; treasurer, D. A. Dunlap, Toronto; secretary, John B. Holden, Toronto; general manager, P. A. Bobbins, Timmins, Ont." While the family company explored stakes and mining operations around the globe; their greatest development was ever the important
Hollinger Gold Mine in
Timmins, Ontario, the city that bears their name. Despite Henry's early reservations, Noah had purchased stakes from
Benny Hollinger and
Alec Gillies, along with several adjacent claims, which were soon incorporated into
Hollinger Mines. Noah had first sent his nephew
Alphonse "Al" Paré, then a geology engineering student, to assess the Hollinger mine's potential. Following incorporation, Noah then put him in charge of operations at the Hollinger Mine for the initial start-up phase of two years. Hollinger Mines became known as one of the "Big Three" Canadian mines, together with the
Dome Mine and the
McIntyre Mines.
The Canadian Statesman reflected, in 1968, that, during the early days of the Canadian mining industry: ==Death==