Haggerty's manager Terry Bomar confirmed to ABC News that the actor died early Friday morning with his family at his side at Providence Saint Joseph Medical Center in Burbank. Bomar said the cancer was detected last August.
Haggerty starred as Grizzly Adams in the 1974 movie "The Life and Times of Grizzly Adams" and the subsequent TV series of the same name, which ran from 1977 to 1978.
The actor also appeared in several other films and TV shows, including "Charlie's Angels" in 1981 and "The Love Boat" in 1983.
Haggerty most recently appeared in "Axe Giant: The Wrath of Paul Bunyan" and "Dead in 5 Heartbeats," both released in 2013.
Bomar said the funeral will be private and a date for a public service will be determined later.
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ABC News contributed to this report.