Based on 1918 newspaper reports (roughly when the mine started shipping), the concentrate was 'sacked' for shipment via the railroad.
Quote
Colorado Historic Newspapers
The concentrate is sacked in double sacks, as the value of the metal - which is now $2.00 per pound - is such that every precaution is taken to prevent loss in shipping. As the shipments are made over the South Park line of the C. & S., it becomes necessary to transfer the shipments to standard gauge cars at Denver.
Source article link: [
www.coloradohistoricnewspapers.org]
It appears that sometime after 1918 the company switched from sacks to barrels. Photo of their warehouse between 1930-1940:
Photo caption:
Warehouse interior filled with barrels to be sent for further processing. Climax Mine between 1930-1940.
That photo is in a Climax Molybdenum company 2018 calendar:
[
www.climaxmolybdenum.com]
.
- Graham