The Jean C. Thatcher family papers (1892-1953) contain a journal written by Jean C. Thatcher. The collection also contains a little booklet of the Thatcher cemetery plot, and a wedding announcement for Jean's brother.

The Paul Thatcher family papers (1809-1972) contain diaries, letters, biographies, and reminiscences from two prominent families of Utah, the Thatcher's of Logan and the Smoot's of Provo.

The Daniel Hadlond Thomas papers (1939-1992) consits of a re-edited version of a biography of Preston Thomas originally completed in 1942. It includes transcriptions of missionary diaries. Also included in the collection is correspondence and a poem written by Thomas.

The George Thomas diary (1849-1868) contains a personal and family record. The journals speak of his conversion to the Church of Jesus Christ of Latter-day Saints (LDS Church).

The Henry B. Thompson diaries (1899-1900) consist of photocopies of the originals detailing Thompson's mission for the Church of Jesus Christ of Latter-day Saints (LDS Church) in Scotland. In these diaries, Thompson describes the challenges that he faced as a missionary. Thompson was appointed president of the Scottish Conference in May 1900 and returned to Utah in June of 1901.

The James Thompson diary (1887-1889) consist of a transcribed copy of the original diary of a missionary for the Church of Jesus Christ of Latter-day Saints. Accompanied by photocopies of family correspondence and genealogical records.

The Vinzenz Thum diary (1919-1922) is handwritten and was kept while on a mission for the LDS Church in Canada and eastern United States.

The Eva Lewis Tiemersma papers (1922-1924) consist of a diary (1922-1924), mission letters, and memorabilia from an LDS mission to the Eastern United States.

The Helon Henry Tracy papers (1875-1889) contain diaries, journals, bookkeeping ledgers, prison inmate rosters, articles, research materials, and newspaper court reports. Tracy was a member of the Church of Jesus Christ of Latter-day Saints imprisoned for polygamy in Utah in 1886.

Incomplete diary (1963) of an LDS missionary, Kurt Randolph Wegner, to the South German Mission.

The Orson F. Whitney papers (1876-1931) consist of photocopies of the diaries, notebooks, and autobiography of Orson F. Whitney, a member of the Quorum of the Twelve Apostles for the Church of Jesus Christ of Latter-day Saints, from 1906 until his death in 1931.

The Elsie Ross Whittaker papers (1915-1947) contain materials relating to being an LDS missionary in the Eastern States Mission from 1922 to 1924, including her diary, a letter from B. H. Roberts, mission circular letters, programs, her patriarchal blessing, and a scrapbook. Elsie Ross Whittaker was born on 22 December 1893 and died in June 1971.

The Feargus O'Connor Willden papers consist of an autobiography/diary of Feargus O'Connor Willden (1864-1878), autobiographical to 1878, then diary entries or transcription 1864-1868; family history to 1955 incorporating a typed transcription of the diary; papers related to an application for an Indian Wars veterans pension; a 1920 Indian Wars Veteran ribbon. Willden was a Utah Black Hawk War veteran and a resident of south-central Utah.

The John R. Winder diary (1857-1858) contains entries from November 1857 to April 1858. Winder (1821-1910) held several positions within the LDS Church.

The Asahel Hart Woodruff journals [photocopies] (1902-1937) detail his life. Asahel Hart Woodruff was the son of Wilford Woodruff. He was president of the LDS Church's Northern States Mission from 1902-1904, bishop of the Waterloo Ward from 1905-1916, and councilor in the Granite Stake beginning in 1916.

The Wilford Woodruff papers (1833-1898) contain a handwritten document by Woodruff regarding the successions of the Mormon Church Presidency, concerning Orson Hyde and Orson Pratt and their placement in line of succession of the LDS Church. Also included are copies of his journal as well as a revelation from 1877. Wilford Woodruff was the fourth president of the Church of Jesus Christ of Latter-day Saints (LDS Church).

The Jabez Woodward diary [photocopy] (1857-1858) was kept while he served as a missionary for the LDS Church.

The Brigham Young papers (1857, 1876-1877, 1908) consist of documents relating to the religious and civic activities of Brigham Young. Included are correspondence, diaries (1837-1857), proclamations, three holograph pages from his will, and microfilm of letter books and official papers from his time as governor of Utah Territory (1849-1857). Brigham Young was the second leader of the LDS Church and was responsible for the movement of the Mormons to the Salt Lake Valley.

The John B. Young papers (1898-1901) contain Young's missionary journal and two photocopied certificates. John B. Young (1866-1946) was a convert to the Church of Jesus Christ of Latter-day Saints (LDS Church) from Scotland who settled in Rock Springs, Wyoming, in 1890. Nine years later, he returned to Scotland as a missionary and was companion to David O. McKay, who later became president of the LDS Church.

The Joseph A. Young journal (1864) details Young's appointment to "take general charge and oversight of affairs pertaining to this year's immigration" of LDS Church members from Liverpool, England, to Salt Lake City.