If Dennis McClendon noticed someone lost in the Loop, he’d ask if they needed directions. He might even pull a little map out from his pocket to pass along.
It was a thrill for him — like a chocolatier giving a kid a piece of chocolate.
What the course-corrected visitor wouldn’t have known was that the mensch with the map was a highly skilled cartographer — Chicago’s Michael Jordan of geographical design.
For years, he was the creator of one of the most iconic and useful guides in Chicago history: the color-coded map of the CTA’s L lines.
His vast output also included the Chicago Bike Map, a series of maps for the American Institute of Architecture guide to Chicago architecture, historical maps for “The Encyclopedia of Chicago” and maps for dozens of transit agencies across the country.
Mr. McClendon, who died Aug. 8 at 67 from complications of cancer, also was part of an elite class of Chicago history buffs — nerds, as he might say.
“If you’re looking for a Chicago fact, no matter how small, it’s always like: ‘Have you tried calling Dennis?’ ” said WTTW-TV host Geoffrey Baer, who occasionally tapped McClendon to explain to viewers some obscure detail about city streets or infrastructure for his “Hidden Chicago” series.
“Dennis is about as close as it comes to being the human form of Google,” said Tim Samuelson, who retired a few years ago as the city of Chicago’s cultural historian. “He had the ability to remember, recall and convey things very accurately and very quickly in the most friendly, matter-of-fact way.”
His firm, Chicago CartoGraphics, created maps for the tourism industry and real estate companies. The last project he worked on was creating the maps of the Near West Side that were provided to all delegates to the 2024 Democratic National Convention.
Mr. McClendon lectured often on maps and history — his subjects including world’s fairs and Daniel Burnham’s 1909 Plan for Chicago — at conferences, universities and at the Newberry Library. In one lecture, he told his audience that a map can be elevated into a “symbol of a city that some love enough to carry the diagram around on the ultimate mobile device” — a line he delivered with an accompanying tongue-in-cheek slideshow image of a foot with a tattoo of his CTA map.
In the same talk, he said he didn’t have a poster of Farrah Fawcett or Chris Atkins on the door of his college dorm room, like many of his classmates did. Instead, he had a Chicago transit map.
“I am proud to be the designer of the successors to that Chicago transit map,” he said.
Mr. McClendon also worked as a tour guide and was tapped to share his knowledge with other guides.
“There wasn’t anything he couldn’t spontaneously give a tour about, he was so knowledgeable,” said Donna Primas, former president of the Chicago Tour-Guide Professionals Association.
“When dignitaries would come to town, he’d be the go-to guy that Choose Chicago” — the agency that promotes Chicago as a tourism destination — “would tap to take them on tours,” she said, noting that Mr. McClendon previously served as vice president of the association.
Mr. McClendon was born July 23, 1957, in Texarkana, Ark., to Noble Lester and Merida McClendon — a small town postmaster and a homemaker.
He was 3 when he discovered there’s no Santa Claus, learning that by reading it in the newspaper, according to his sister Denise Carriveau.
He spent many hours constructing tiny roads and cities in a sandbox and out of blocks, created inventions out of household items, read everything he could get his hands on — cereal boxes, advertising mailers, railroad timetables — and began signing his name Dennis McClendon PTG (part-time genius).
He started collecting maps from a young age and would be the family navigator on road trips even though his dad almost certainly knew the route, according to his sister, who’d be lectured if a map wasn’t folded just so.
“In high school, I heard there was a way of hacking into touch-tone phones, but Dennis actually knew how and had the equipment, so that made him pretty cool, and he introduced me to Elton John,” said his high school friend Steve Nobles, noting that Mr. McClendon was a teenage disc jockey for a radio station. “He was just a cool radio DJ, geeky, really smart guy, and he never talked down to me.”
Mr. McClendon got a scholarship to Tulsa University, where he majored in urban studies, then attended law school at the University of Texas but didn’t end up working as a lawyer.
“Dennis told my parents he wanted to go to law school for the knowledge …. and then only took the bar exam at my parents’ insistence,” his sister said.
His first job brought him to Chicago, where he worked in the legal research department of an accounting firm.
He later worked or the American Planning Association and helped produce maps for its monthly publication before starting his own mapmaking business.
He was a largely self-taught cartographer and designer, according to his sister.
He posted diverse maps of Chicago on a website he created — www.chicagoinmaps.com — and maintained a formidable presence on Reddit, on which he weighed in on many subjects about Chicago under the screen name “MrDowntown.”
A longtime member of the North American Cartographic Information Society, he was founder and host of its annual “GeoDweeb Geopardy” competition.
For more than 40 years, he lived in a condo near Printer’s Row, and he was very involved in the South Loop Neighbors organization, where he was a longtime leader and face of the group.
“He advocated for smart and sustainable development,” said Jack Chalabian, vice president of the group. “He had a natural presence, and he leaves a huge void.”
An avid world traveler, Mr. McClendon loved to learn about how locals lived by visiting a grocery store or having lunch in a park.
Mr. McClendon was generous in sharing his knowledge but not in a pretentious way, according to Samuelson, who said: “He didn’t brag. He had a lot he could brag about, but he didn’t do it. If you asked him something, he’d tell you in a cheerful, forthright manner.
“We would go in the early days of Millennium Park, and we’d meet and set out a blanket on the grass to hear a concert, and Dennis would always bring a big bucket of Colonel Sanders chicken, and I always thought that was just great — he wasn’t bringing sushi,” Samuelson said.
“His goal in life was to eat all the meat pies in the world, from empanadas to pierogies and on down the line, anything bread dough and meat,” Nobles said. “He would not eat vegetables. Period. His entire life. He would not eat a sandwich even if a piece of lettuce had laid on it briefly.”
Mr. McClendon didn’t own a car. He’d get around on his black mountain bike, which had metal baskets on the back, and was a regular presence at Golas and Sons Bike Repair, where he was friends with owner Matt Golas.
“We were on a community ride once and stopped for water, and I was thinking out loud, ‘Gee, I wonder how many bridges there were at the time of the Chicago Fire?’ ” Golas said. “And Dennis kind of looked off and began counting bridges in his mind.”
In addition to his mother and sister, Mr. McClendon is survived by nephews David and Michael Carriveau and his niece Sara Monfries.
A memorial is planned at 5 p.m. Sept. 9 at Grace Place Episcopal Church, 637 S. Dearborn St.