Don Imus, who spent more than half a century in radio and television skating along the edge of propriety and occasionally falling into the abyss of the unacceptable, died Friday at a hospital in College Station, Texas. He was 79.

His family announced his death in a statement. The cause was not immediately available.

In a roller-coaster career in which he grew chummy with prominent politicians, repeatedly got suspended or fired for offensive cracks, abused drugs and touted health foods, Imus won a loyal following, made millions and transformed himself from a bad-boy DJ into a host whose program became a nearly mandatory stop for presidential candidates.

In his later years on the radio and on TV, Imus pioneered a form of talk show that went both low and high, reaching for cheap yuks even as he created a place in pop culture for discussion of serious literary and political topics.

By breaking the rigid format of Top 40 hit music radio and injecting brash, irreverent satire, Imus opened the door to a generation of even coarser radio DJs and talk show hosts, such as Howard Stern, "Mancow" Muller, and Opie and Anthony. And by turning his show into a raucous salon for Washington politicians and news celebrities, Imus created a bridge between the nation's leaders and disaffected citizens who largely tuned out politics.

Imus, known to listeners as "Imus in the Morning" and "the I-man," was a high school dropout, a railroad worker and a singer-songwriter who rattled around playing Top 40 records on tiny California AM radio stations in the late 1960s. As "Jay Jay Imus," he recorded pop tunes with his brother Fred.

He quickly discovered that wild pranks and bad behavior were a surefire path to big ratings and widespread acclaim. He got fired from a station in Stockton, Calif., for saying "hell" on the air; in later years, that would be one of the milder cuss words in his repertoire.

In 1969, at KXOA in Sacramento, he called up a McDonald's and, posing as a National Guard sergeant feeding his hungry troops, he ordered 1,200 hamburgers to go — "now listen, on 300 of those, I want you to hold the mustard but put on plenty of mayonnaise and lettuce." The entire zany exchange aired live.

Posing as a "Mr. Huey," he called the Tyde Dyde Diaper Service seeking extra-extra-large diapers for his exceedingly large baby, whose name, it turned out, was "Baby Huey."

Even in those early shows, Imus was building toward harder-edged fare that would win him notoriety in a less-innocent era. He greeted young female callers with a leering "Are you naked?" He spoofed evangelicals with his lunatic preacher character, the Right Rev. Billy Sol Hargis, pastor of the First Church of the Gooey Death and Discount House of Worship. He imitated NBC News anchorman David Brinkley in bits poking fun at politicians.

At his best, the husky-voiced Imus created memorable comedy that won comparisons with classic radio performers such as Stan Freberg or Bob and Ray. At the same time, Imus was given to ugly personal attacks and racial slurs that diminished his reputation and derailed his career.

A frequent guest, commentator Jeff Greenfield once called Imus "the court jester to the powerful," whose show was "a very comfortable place to have real conversations about real stuff." But others viewed him as an egotistic faux-cowboy who picked on the weak and gave voice to ugly stereotypes.

"I could never figure out if there was really a heart of gold under that crusty, nasty old leathery soul of his," said David Von Drehle, a Washington Post columnist who worked with Imus' second wife, Deirdre, on a book she wrote about vegan cooking. "He had such a dangerous job. You're supposed to push the envelope constantly, but never step over the line."

After years on the edge, Imus went too far on April 4, 2007, when, in his trademark drawl, he referred to the Rutgers University women's basketball team, which had reached the NCAA finals and was composed mainly of black players, as "rough girls" and "nappy-headed hos."

An outcry by black organizations, women's groups and the news media ensued, and his radio show was yanked eight days later by CBS Radio.

John Donald Imus Jr. was born July 23, 1940, in Riverside, Calif., to a well-to-do local beauty and a third-generation cattle rancher.

Besides Deirdre, his wife of 25 years, survivors include four daughters from his first marriage and two sons from his second marriage.

The New York Times and Associated Press contributed to this report.