Harlan Draeger, a versatile, prolific news reporter who once said “I was interested in the dark underbelly of Chicago,” has died at 90.

Mr. Draeger’s influence went beyond the thousands of stories he did for the Chicago Sun-Times and, before that, the Chicago Daily News, Kenosha News and Wisconsin Rapids Daily Tribune. Admiring colleagues sought out his advice. And he’d lobby editors to give reporters the time to work on investigations he felt would benefit the public. “This is a rich story,” he’d tell them.

Mr. Draeger died Thursday at Froedert South Hospital in Kenosha, Wisconsin.

Commuting by train for decades from Kenosha to work in Chicago, Mr. Draeger reported on corrupt contracts at McCormick Place and crooked city courts during the Operation Greylord probe. He worked on environmental stories about toxic dumps and a giveaway of coal reserves on public and Native American lands. He investigated deteriorating Chicago parks. And he wrote about mobsters and madams.

He even covered the apprehension of Ed Gein, a Wisconsin grave-robber and serial killer whose story is said to have inspired “Psycho,” “The Texas Chainsaw Massacre” and “Silence of the Lambs.”

In a 42-year career, he won many honors, including sharing in four Peter Lisagor Awards for Exemplary Journalism, given by the Chicago Headline Club, and was inducted into the Chicago Journalism Hall of Fame.

Mr. Draeger had a keen ability to call up details about long-past misconduct. Even in recent years, Chicago reporters would pick his brain while investigating contemporary corruption with roots in previous decades.

His desk was piled with stacks of documents that obscured him from view. But in those piles was investigative gold.

“If you asked Harlan about somebody you needed information on, he would reach into his files and pull out one of these memos with more good tips and leads than I could compile in a month,” Sun-Times columnist Mark Brown said.

“Not only was his output prodigious, but he was so exacting and paid so much attention to detail,” said Maurice Possley, a former reporter for the Sun-Times and Chicago Tribune and senior researcher for the National Registry of Exonerations. “I learned a lot from him.”

“He could do anything, and he was very accurate,” said former Sun-Times writer Bob Herguth Sr.

He was a mentor to many young reporters.

“One day, he pulled me aside and said, ‘Why do you dress so terribly?’ ” said Andrew Herrmann, a former Sun-Times reporter who’s now communications director for Friends of the Chicago River. “He explained that a reporter needs to reflect a certain respect. . . for himself, for the source and for the institution. Dressing decently also put you closer to the same level as the source.”

Herrmann bought some new clothes.

Mr. Draeger’s writing flair showed in a 1976 Daily News story on the death of Mayor Richard J. Daley, in which he wrote: “He was the symbol of the city, its undisputed leader, father figure, protector and provider, the indispensable man, the irreplaceable part. Now he is gone. Nearly all Chicagoans — even those who disliked his brand of politics — feel a sense of loss.”

He started one Sun-Times story this way: “Who says Chicago ain’t ready for reform? Not one city alderman was indicted or convicted on corruption charges during 1991. In most communities, such a year-end statistic wouldn’t rate a mention. But extended aldermanic visits to federal prisons have become a regular, if embarrassing, feature of Chicago’s civic life.”

Born and raised in Beaver Dam, Wisconsin, Mr. Draeger served in the Army in the United States and occupied Japan. He went to college on the GI Bill, earning a bachelor’s degree in journalism from the University of Wisconsin.

During the Blizzard of 1967, he displayed his versatility by doing an emergency weather report for WFLD-TV from the Daily News.

He joined the Sun-Times in 1978, after the Daily News folded. He retired in 1992.

He enjoyed a cold gin martini and loved to fish. For more than 60 years, he’d join friends each May on a trout-fishing expedition to Waushara County, Wisconsin, sending out the invitations with news of milestones in the anglers’ lives and quirky fishing news.

In the 1970s, he was a president of the Chicago Newspaper Guild.

As a private citizen, he worked to bring a four-year University of Wisconsin branch to the Kenosha-Racine area. And in the mid-1950s, he helped organize an 800-person statewide committee to preserve public radio in Wisconsin.

He and his wife, the former Rita Meier, had been married since 1957. He is also survived by his son Paul, daughter Ann-Marie and three grandchildren.

Visitation will be at 11 a.m. March 16 followed by a noon memorial service at Draeger-Langendorf Funeral Home in Racine.