Step aside, goat yoga. The chic way to unwind now is fly fishing.

That’s right. For some of the same reasons millennials recently flocked to bird-watching, this sport — long dominated by old white men — is gaining popularity with a younger set.

For those who can afford the leisure time and some rudimentary equipment, it offers a reason to be outdoors, a closer connection to nature, an avenue for environmentalism, built-in community, opportunity for creative expression, and a lifetime’s worth of niche expertise. Fly anglers who are not vegetarian nor vegan, nor otherwise bound by the code of “catch and release,” see it as an extension of the farm-to-table movement. Plus, it’s very Instagrammable, even as it encourages people to put down their phones.

And where millennials go, hospitality brands follow. Guided fly-fishing excursions are now offered at many trendy boutique hotels, including The Little Nell in Aspen, Colo.; Tourists, the eco-friendly lodge opened by indie influencers including the bassist of Wilco, in North Adams, Mass.; and Sage Lodge, a new nature resort just north of Yellowstone National Park in Pray, Mont., which has a stand of fly tackles and nets in its lobby, and daily “Fly Fishing 101” courses at its backyard casting pond overlooking the Absaroka Mountains.