Election results from individual county canvass reports mainly via Utah Lieutenant Governor’s Office (https://vote.utah.gov/obtain-voter-registration-or-election-data/).
Precinct shapefile from Utah Geospatial Resource Center (https://gis.utah.gov/data/political/voter-precincts/).

The shapefile from UGRC is of subprecincts, breaking down precincts in cases of district splits. In many counties results are reported at the subprecinct level, but for counties where results are instead reported at the precinct level subprecincts are merged accordingly.

In Grand County, the aggregate precinct results for US Senate include one more vote for McMullin (I) than the certified countywide total. This appears to have been a write-in vote later counted for McMullin.

Write-in votes are not directly comparable between counties. Some counties only report official write-ins while others also include invalid write-ins in the precinct results. Utah County did not record any write-in votes by precinct.

G22USSRLEE - Mike Lee (Republican Party)
G22USSIMCM - Evan McMullin (Unaffiliated)
G22USSLHAN - James Arthur Hansen (Libertarian Party)
G22USSAWIL - Tommy Williams (Independent American Party)
G22USSOWRI - Other Write-in Votes

G22TREROAK - Marlo M. Oaks (Republican Party)
G22TRELBUC - Joseph Geddes Buchman (Libertarian Party)
G22TREUHOR - Thomas Alan Horne (United Utah Party)
G22TREAROG - Warren T. Rogers (Independent American Party)