The 100 block consists of 1.1 metres of files pertaining to the general administration of the Northern Administration Branch of the federal government. Included in the files are minutes of staff meetings and conferences, records relating to the relationship between Federal and Territorial governments including financial agreements and transfer of responsibilities, organizational charts, personnel information including policies and directives, band membership returns, and correspondence relating to these subjects. Some of these files also contain photographs. This block consists of files 1-1 to 9-2.

The record is comprised of a handwritten one page census report for 1871 'Statement of the Indian population of the Mackenzie River District', listing total numbers of Indian (Indigenous) residents by Men/Women/Children (boy/girl). Posts reported include: Youcon [Yukon], LaPierre's House, Peel River, Fort Good Hope, Fort Norman, Bear Lake, Fort Nelson, Fort Liard, Fort Simpson, Fort Providence, Hay River, Fort Resolution and Fort Rae.