Expecting a call may come in early summer, Gardner said he wanted to forewarn party leaders about his intentions.
"I haven't made my [interest in a mission] a secret or anything," he said. "But I wanted to be transparent so that when the County Council goes through the [replacement] process, people will know it's an open process and anybody who wants to throw their hats into the ring can do so."
While Gardner feels some of his top aides in the assessor's office are well qualified to assume his duties, he said he has heard of outside interest in the position.
"I wanted to ensure there wasn't any appearance something was being done secretly," he said. "I have a responsibility to the public to ensure it's a totally open process."
County Republican Party Chairwoman Julie Dole said that when Gardner officially steps down, a successor will be picked in a special election involving almost 800 members of the party's central committee.
Gardner was a State Tax Commission appraiser in 1994 when he defeated Democrat David Swan, a colleague in that state office, in an election to replace retiring Republican Assessor Robert Yates.
At the time, his office employed 108 people to maintain records on each piece of taxable "real" and "personal property" in the county roughly 264,000. Since then, the number of parcels has increased since to 345,000 while the size of his office staff declined slightly to 105.
Gardner was re-elected for the first time in 1998, besting Democrat Bob Adams. In the next three elections, he defeated Democratic foes Liz Fehrmann (2002 and 2010) and Josie Valdez (2006). He won all five elections handily, receiving between 56 and 60 percent of votes cast.
During his 18 years in office, Gardner said his major accomplishment was creating equity in the assessment process. Rather than reviewing sections of the county every five years, he revised the rolling system to spare home and business owners some shock each fifth year when the value of their properties would escalate, resulting in higher taxes.
He also cited his decision to stand by his assessment of Alliant Techsystems' property in Magna. The company challenged the assessment all of the way to the Utah Supreme Court, which ruled in the county's favor in 2005.
The former State Tax Commission appraiser has won five elections over Democrats since 1994, when Republican Robert Yates retired as Salt Lake County assessor:
1994 • Defeated David Swan, 58-42%
1998 • Defeated Bob Adams, 59-41%
2002 • Defeated Liz Fehrmann, 58-42%
2006 •Defeated Josie Valdez, 56-44%
2010 • Defeated Fehrmann, 60-40%
Source: Salt Lake County Clerk's Office