When searching the population schedules of the 1850 federal census in Utah, it's important to remember that polygamy was widespread and also illegal. When the government representatives visited to record information about a household, many of the women used maiden names or earlier married names rather than document their polygamous marriage in a federal record. It's also important to realize that the 1850 census of Utah was actually enumerated in 1851. Although the data was supposed to be recorded as of the census day, 1 June 1850, ages and household residents frequently reported information accurate for 1851.
In 1850, Archibald Gardner was married to three women, and he married a fourth wife in 1851. However, the census appears to record one wife. Below is the census record of Archibald's household. Notice that he is enumerated with his first wife, Margaret, and their children. [1850 U.S. Census of Salt Lake County, Utah, p. 100, household and family number 471.]
On the next page of the census, the first household enumerated is that of Abigail Bradford, Archibald's second wife, who was using a previous married surname. Abigail's first child was Mary Ann, who was also married to Archibald, but was listed under her maiden name. The household listing then includes the remainder of Abigail and Hial Bradford's children, ending with two of Archibald's children. Abigail Gardner, daughter of Abigail and Archibald, was listed as Abigail Bradford. Mary Elizabeth Gardner, daughter of Mary Ann and Archibald, was listed as Elizabeth Bradford. The last person in the household, Elizabeth Lewis, appears to be an unrelated person. In fact, she was Archibald's fourth wife. [1850 U.S. Census of Salt Lake County, Utah, p. 101, household and family number 472.]
Notice that Archibald's brother, Robert Gardner, was listed next, with Archibald's parents, Robert and Margaret Gardner, a few entries further down the page.