Alexander McKay (1832-1922), a Scottish immigrant, was a miner and businessman in Virginia City, Montana. Records (1857-1922) include correspondence, financial records, legal documents, and court papers for McKay's business interests including flour mills and mining claims. There are subgroups for Elling, Baker McKay (1887-1911); Mill Creek Mills (1878-1898); Caroline Hanson McKay (1877-1911); and Mary McKay Herhold Bothwell Swanze (1876-1925).

The Merchants National Bank of Helena, Montana, was originally established as L.H. Hershfield and Co. in Virginia City, Montana Territory, and for many years operated as L.H. Hershfield and Bro. It went into receivership in 1897. Records (1865-1903) consist of correspondence, financial records, legal documents, and organizational materials. There are subgroups for the White Sulphur Springs Association and for the United Hebrew Benevolent Association.