It's been almost a half century since a Kennedy visited the Yukon.

The last time, U.S. Sen. Robert Kennedy joined a National Geographic team as they scaled Mt. Kennedy in 1965.

He did it in tribute to his older brother, president John F. Kennedy, who had been assassinated two years earlier.

Next month, one of Robert's sons, 59-year-old Robert Kennedy Jr., will take his family on a guided rafting trip down the Alsek River.

After the trip, which is expected to give the family a glimpse of Mt. Kennedy, the long-time lawyer plans to share his message of environmental preservation with a Yukon audience.

In a speech called Our Environmental Destiny, Kennedy will discuss the role natural resources play in our work, health and identity; and our responsibility to protect and preserve the planet for future generations.

A lawyer by trade, Kennedy has devoted much of his life's work to environmental issues.

He serves as the senior attorney for the Natural Resources Defense Council, the chief prosecuting attorney for the Hudson Riverkeeper and is the president of the Waterkeeper Alliance.

He's also been named one of Time magazine's "Heroes for the Planet” for helping Riverkeeper in its fight to restore the Hudson River.

Kennedy started the Waterkeeper Alliance in 1999 as a citizen advocacy organization focusing on issues affecting our waterways.

Globally, there are now 207 Waterkeeper programs within the alliance, including nine in Canada.

Neil Hartling, the owner of Nahanni River Adventures, will guide Kennedy's trip down the Alsek. He said he never passes up a chance to go down the river.

But Bobby, as Hartling referred to Kennedy, is "skilled enough that he could this himself. He's quite an accomplished paddler.”

His last trip was down through the Grand Canyon.

He went with Wade Davis, a Canadian anthropologist and an explorer-in-residence with National Geographic, and the two made an Imax movie of their adventure.

"The Grand Canyon is the epicentre of the white water world. Anybody who's run a rapid in a boat has somewhere in the back of their mind that their ultimate experience would be to paddle and hike in the Grand Canyon,” Hartling said.

"All of the guides down there are regarded as the gurus, and if you ask any one of them where they dream of going, they'll tell you the Alsek River.

"So that's why Bobby's coming here; it's one of the big reasons he's coming here.”

As it stands, Hartling is preparing for a group of about 18.

They plan to put in Aug. 2 and will return to Whitehorse Aug. 7, in time for Kennedy's talk at the Yukon Arts Centre at 8:00 that night.

"The Alsek is a river of superlatives,” Hartling told the Star this morning, clearly passionate about the waterway.

"It flows through the world's largest non-polar ice sheets, you go through Lowell Lake, which has apartment-sized icebergs floating around on it, the Lowell glacier comes down to the lake and calves these bergs into the lake. It's a fairy tale setting.

"And then you hike up onto goat herd mountain and see mountain goats and look down over the Lowell glacier and Lowell Lake. And the river itself is teeming with grizzlies and tremendous wildlife viewing.”

One section he described as "the closest viewscape that we have in North America to the Himalayas; very rugged and dramatic.”

Hartling said he was really looking forward to guiding the trip, partly because he'll be guiding a Kennedy, but it's more than that.

"He has some very unique world experiences with rivers and wilderness. I'm interested to share his knowledge and his experiences, and hear his stories,” he said.

Kennedy's father was assassinated in the Ambassador Hotel in Los Angeles in June 1968.

He had just finished addressing a jubilant crowd while seeking the Democratic nomination for that year's U.S. election.

His assassin, Sirhan Sirhan, remains imprisoned.