Ephraim Peter Jensen was born on November 4, 1857 in Brigham City, Utah to Hans Peter Jensen and Sarah Josephine Clausen who were pioneers of Brigham City. Sarah was the second wife of his thirteen wives.

During his young days Ephraim worked on his father's farm. At one time he was very active in sports, holding the title of champion wrestler of the State of Utah. In 1876, he played in the Marshall Band in Brigham City, and in the same year was called as a missionary to assist in moving the members of the Church who had been called to settle in southern Utah and Arizona. It was at this time that he saved President Daniel H. Wells from drowning at Lee's Ferry.

Ephraim received his early education in Brigham City and graduated from a course in geology at the Utah State Agricultural College in Logan, later graduating from the University of Utah, then called the University of Deseret. Returning later, he engaged in railroading and teaming. Ephraim attended the University of Utah in 1882 and went on another mission to the Northern States in 1883.

On May 1, 1884 Ephraim married Mary Harriet "Hattie" Critchlow of Ogden. He engaged at different times in merchandising, stockraising, farming, insurance and real estate. During 1885 Ephraim taught school in Brigham City.

In 1889 he became Sheriff and Justice of the Peace in Brigham City. Ephraim went on a third mission in 1898 to the Eastern States, and he reopened on Boston Commons, the work which had been closed to missionaries for many years.

When Ephraim returned from his mission in 1900, he moved his family from Logan to Salt Lake City, where he had been called by President Lorenzo Snow, his brother-in-law, as a Custodian of the Tabernacle. While engaged in this, he established the Bureau of Information. He explained the gospel to hundreds of tourists who daily visited the Tabernacle grounds.

Ephraim and Hattie divorced. Later he married Mary Elizabeth McDonald on December 2, 1916. Ephraim died in a local hospital at the age of 81 on October 24, 1939 and was buried in the Salt Lake City Cemetery on October 27, 1939.