The 1850 US Census lists slaves listed in Utah County (draft and official).
Utah Territorial Census Schedule 2 for Utah County, 1851, MS 2672, The Church History Library
[Names of enslaved persons on the 1850 census draft]
Vilate
Toby
Grief
Oscar
Nelson
Mary
Henderson
Rose
Nancy
George
Philemon
Tennessee
Hark
Harriet
Hannah
Biddy
Ellen
Ann
Harriet
Ann
Samuel
Nelson
Joanne
Charley
[List of slaves found in the official 1850 Census]
Vilate
Toby
Grief
Oscar
Nelson
Mary
Henderson
Rose
Nancy
George
Philemon
Tennessee
Hannah
Biddy
Ellen
Ann
Harriet
Ann
Lawrence
Nelson
Jane
Charley
Hark
Harriett
The first image is the original census taken by Thomas Bullock and the second is a copy made by Robert Campbell. Both censuses note that all of the enslaved individuals will be traveling to California.