The Navajo Sheep Project papers include newsletters, pamphlets, and other materials created by the nonprofit organization focused on preserving the Navajo-Churro sheep, an endangered breed important to the Navajo (Diné) people.

Mainly correspondence, business receipts, and bank statements dealing with Nielsen's various business enterprises during 1892-1927. Companies represented here include A. J. Knollin and Co. of Missouri; partnerships with E. J. Kearnes and B. R. Meek in sheep, land, and livestock operations in Utah and Idaho; the Blue Creek Land and Livestock Company of Utah; the Riverdale Ranch near Preston, Idaho; and the Pacific Reclamation Company of Metropolis, Nevada.