Brian O'Connor completed a decades-long quest at nearly 12,000 feet above sea level last week.

Around 10 a.m. on July 14, O'Connor crossed the Clear Creek County line at the top of Loveland Pass, completing his goal to visit all 3,143 counties and county equivalents in the United States.

“I could talk to anyone (from the U.S.) and say, `I've been in your county,” he said.

O'Connor, a math professor who lives in Cookeville, Tennessee, started his quest in 1970, when he and a friend spent a month traveling around the country. However, it wasn't until a few years later, when he bought a road atlas with every county listed, that he started keeping track.

Since then, he's been taking trips — mostly with family members — and recording his progress on a spreadsheet.

While he's not the first to visit every county, his fellow adventurers have speculated that he might be the first to finish the quest in Colorado and at such a high altitude.

Before he flew back to Tennessee on July 14, he drove down from Loveland Pass to visit the Clear Creek County courthouse and downtown Georgetown.

“Some place has got to be the last one,” he said as he sat at a table along Sixth Street. “… It was a good county to end on.”

Going the extra mile

O'Connor is a member of the Extra Miler Club, a group of individuals completing similar quests. In honor of his recent accomplishment, the club will award him a plaque at its national meeting Aug. 7 in Covington, Kentucky.

According to the club's website, most members are trying to visit every U.S. county and equivalent. However, others are collecting national parks, state high-points, golf courses, baseball stadiums, county courthouses, interstate highways and others.

The club was founded in 1973, and since then, at least 65 members have completed the all-county quest.

The most recent, according to the website, was Colorado resident Charlie Anderson, who finished in 2019 in Kentucky. He also took photos of all the county courthouses.

While Anderson and other club members document theirs quests with photos or receipts at every stop, O'Connor said his worked on the honor system. He and many fellow Extra Milers also operate under the notion that while flying over counties doesn't qualify, driving through them does, he explained.

Plus, some areas in the United States technically aren't counties at all, but county equivalents.

The U.S. Census Bureau applies this term to Alaska census areas and boroughs; Louisiana parishes; independent cities, such as Baltimore and St. Louis; and the District of Columbia.

The grand tour

During his quest, O'Connor spent more time in some areas than in others. For some, he simply drove to just over the county line and turned around, while he drove through others.

For many, though, he stopped to admire the courthouses, museums, college campuses, national parks and other sites.

“I like being on the road, seeing different things,” he said, adding that he doesn't like staying in one spot while on vacation.

Along with his home counties in Illinois and Tennessee, O'Connor said his favorite areas to visit included Colorado's Fremont and Chaffee counties; Brewster County, Texas, where the Big Bend region is; and Cherry County, Nebraska, home of the Sandhills.

Among the more challenging ones, he listed northeast Oregon and Florida's Everglades region. He described trying to visit Monroe County, Florida by a road that was basically a rut through the jungle.

Alaska, as a whole, was probably the most challenging, with O'Connor explaining that many areas were only accessible by plane. It took him three separate trips to Alaska to collect all its boroughs and census areas.

“I got to know the Anchorage airport really well,” he said, explaining that most of his flights to rural Alaska were out of there.

After collecting his final six areas in Alaska in June, O'Connor planned his final trip for July 6-14 to visit his final dozen or so counties in Colorado.

For anyone contemplating or attempting to collect counties or anything else, O'Connor said they should be prepared for a lot of flying and even more driving.

“Planning is key,” he continued.

As he reflected on all 3,143 counties and equivalents he's visited, O'Connor stated, “I think I saved the best for last.”