These cruises, which generally run $1,000 to $4,000 a passenger, usually follow the aquatic path Muir popularized, departing from Seattle or Vancouver with stops in Ketchikan, Juneau and Skagway.

As the green shoreline of British Columbia scrolled slowly past behind a blue-gray screen of mist, I thought of Muir’s last trip to Alaska, as a member of the Harriman Expedition in 1899.