Byron “Barney” Olsen parlayed his longtime love of cars and trains into both a career and a calling.

The St. Paul native worked in railroad law — he was the Soo Line’s general counsel for a time — and wrote several books on vintage cars and trains. He collected classic cars, too, his prize a stately 1935 Lincoln.

“He had a love of automobiles, and really anything with wheels — trains, streetcars,” said Thomas Warth, a friend, fellow classic car buff and publisher of some of Olsen’s books.

Olsen, of Roseville, died July 9 of a brain tumor. He was 84.

Olsen grew up in St. Paul’s Merriam Park neighborhood and went to Grand View College, then a two-year institution in Des Moines run by the Danish Lutheran church. There he met Alis Mortensen. They married in 1956 after graduating from Grand View and moving to Minneapolis, both to finish their undergraduate degrees at the University of Minnesota.

Olsen went on to law school at the U and after graduating landed a “dream job” — as Alis put it — working in the law department of St. Paul-based Great Northern Railway (which in 1970 became part of the Burlington Northern).

Olsen eventually moved to the Minneapolis-based Soo Line, where he was instrumental in a key deal. The Soo Line in 1985 bid on the bankrupt Milwaukee Road. So did the Chicago Northwestern, and it was willing to pay 35% more than the Soo’s $570 million offer. Olsen argued in bankruptcy court that the Soo Line’s bid would be better for the Milwaukee Road’s workers and the communities it served; fewer employees would be laid off and far less track abandoned.

Much to the chagrin of the Milwaukee Road’s creditors, the judge chose Soo Line’s bid. “The whole industry was shocked,” said Ken Buehler, executive director of the Lake Superior Railroad Museum in Duluth. Olsen was a member of the rail museum’s board of directors from 1980 until his death.

After the Soo Line, Olsen worked in transportation law at the Felhaber law firm in Minneapolis until retiring in 2000. When he wasn’t lawyering, Olsen was digging through photo archives and writing.

He wrote a pictorial history of the Great Northern from 1945 to 1970 and did the same for classic Nash, Buick and Chevrolet automobiles. He also wrote a book on station wagons, co-wrote a tome called “The American Auto Factory” and authored a regular column for the magazine Old Cars. He was an encyclopedia of car history. “Most car enthusiasts now, they know everything about Corvettes, but nothing about a Rolls-Royce,” Warth said. “Barney knew about them both, and everything in between.”

Olsen’s specialty was “original” cars: classic vehicles that hadn’t been restored.

In the late 1980s, while walking in his St. Anthony Park neighborhood in St. Paul, Olsen spied a 1935 Lincoln on blocks in an open garage. The luxury sedan with a V-12 engine had not been driven in over 40 years, and its odometer was below 20,000 miles.

“It was a gorgeous car,” Alis said. Olsen bought it “and gradually brought it back to life.”

The Lincoln wasn’t just for show; Olsen toured in his classic cars. “We drove the Lincoln to Thunder Bay,” Alis said.

In addition to his wife, Olsen is survived by daughter Carla Larsen; son Peter; two granddaughters; and a brother, Glen Olsen. A memorial service will be held at 2 p.m. July 30 at White Bear Unitarian Universalist Church.