Nearly 30 years after joining “Entertainment Tonight,” Mary Hart said she still has mountains to climb. Literally.

The “ET” host, who announced Thursday that she’ll depart the entertainment newsmag, plans to scale Mt. Kilimanjaro after signing off in May.

Beyond that, “I don’t know what I’m going to do,” Hart told Daily Variety. “I’m not using the ‘R’ word. I have no intentions of retiring. There are other opportunities out there.”

Hart is exiting “Entertainment Tonight” after her upcoming 30th season on the landmark syndicated entertainment newsmag. With her contract up, Hart said she felt the time was right.

“In my press release, I said I never meant to be here more than three years, and all of a sudden we’re looking at 30,” she said. “Time has flown by. I consider myself the luckiest person on the face of the Earth.”

Hart said she’s grappled with whether to stick with “Entertainment Tonight” for years.

“Every time my contract has come up, I’ve said, ‘That’s it.’ I said it at 15 years, I said it at 20 years, I said it at 25 years,” she said. “But this time, as I look at my son going off to school, I’ve taken stock of the other things in my life … I’m not gunning for 40 years.” In her release, she added, “There are many things I want to do in my life, and I’d better get on with them.”

Hart has been with “ET” since 1982. Rumors of her exit had swirled in the past few days, with talk that “The Insider” anchor Lara Spencer might be in line to replace her.

CBS TV Distribution has made no final decision on Hart’s replacement.

“It is not my job to decide who will be my successor,” Hart said. “But I love my job, and I’ve always said you’d be crazy not to want my job. … When the decision is made, if it’s Lara or whoever, I hope they cherish it as much as I have.”

Other candidates on the shortlist would include “ET” weekend anchor Samantha Harris, formerly of “Dancing With the Stars.”

Hart’s exit means two major syndication stalwarts will be exiting the business after 2011: Hart joins Oprah Winfrey, who is ending her syndie strip — also distributed by CBS — at the end of the upcoming season as well.

Hart said she wasn’t influenced by Winfrey’s decision and noted that another longtime TV icon, Larry King, also recently announced his exit.

“Her timing is her timing, and mine is mine,” Hart said.

Nonetheless, that’s a tough turn of events for CBS TV Distribution, which will now be saying farewell to arguably its two top stars at once.

“‘ET’ and Mary Hart have created the genre of entertainment news,” said CBS TV Distribution prexy John Nogawski. “Not only has she defined ‘ET’ for almost three decades, but she’s defined entertainment journalism. Revered by both the entertainment community and viewers, Mary has been a fixture in our lives and we’ll miss her dearly.”

And longtime exec producer Linda Bell Blue said she would miss Hart “tremendously.”

“Right now we are focused on making this next season the very best in her long history with ‘ET,'” Bell Blue said. “She will remain first on the red carpet for the biggest award shows and will continue to interview Hollywood’s top stars.”

Hart said she knows “Entertainment Tonight” gets hammered by critics, and said the show has been knocked from the start.

“People couldn’t wrap their minds behind the idea of putting on a half-hour of entertainment news,” she said. “I took (that criticism) with a grain of salt … just like being called ‘too damn perky’ you take with a grain of salt. People spend billions of dollars on entertainment every year.”

Among her more memorable beats, Hart said the serious stories that “ET” revealed, such as the illnesses of Richard Pryor and Annette Funicello, were the ones she remembered the most.

“It’s those stories that left a deep impression on me,” she said. Hart said she also appreciated the ability to cover the 2008 presidential election.

As “Entertainment Tonight” evolved through the years, it has also faced more competition — both on-air and on online. And as even hard-news operations started covering more entertainment and pop culture, the field has gotten crowded.

But “we were the first and I still think that we’re the best,” Hart said. As “Entertainment Tonight” hits 30 years, she called it “a phenomenal achievement … the first three years, people said it wouldn’t last.”

Of course, Hart is also famous for the legendary tale of her legs, once insured by Lloyd’s of London. Asked if that’s still the case, Hart was coy: “Maybe it’s time to renew that policy.”