McLeod became a trader and brigade leader with the Hudson's Bay Company (HBC), led by Sir George Simpson, after they joined with the NWC in 1821.
He was highly active in solidifying the HBC role in the Pacific Northwest and was instrumental in George Back's Arctic expedition, as well as in establishing the Siskiyou Trail between Fort Vancouver and the Sacramento Valley of California.
[1] Based at Fort Vancouver, McLeod explored the Umpqua and Rogue rivers in 1826–28, and was preparing his brigade for another departure in July 1828 when American explorer Jedediah Smith arrived there after most of his party were killed by Umpqua people in Oregon.
[2][3] Alexander McLeod was a maverick in the eyes of the HBC but was an important employee who served the company in a variety of settings.
John Ballenden, who married McLeod's daughter Sarah, later achieved this position with the company.