Property tax receipts for Swalley's ranch north of the Boise River, Ada County, Idaho (1865-1896); and commission as second lieutenant, Idaho territorial militia, 1st regiment, 1st brigade, Idaho Volunteers (1877).

Correspondence and financial and legal documents. Personal letters from Johnston to family members describing daily life in Idaho Territory; Ada County tax receipts; discharge papers from Idaho Volunteers following service in Nez Perce War; Johnston's personal account book; and a typed biographical sketch of Johnston (which uses the name T.T. Johnson). Photographs are also present.