The past year has been among the best and worst of times for serious mountaineering.

In December, the American teenager Jordan Romero became, at 15, the youngest person to scale the world’s seven top peaks when he reached the 4,892-meter, or 16,000-foot, summit of Vinson Massif in Antarctica. That is a feat that only 348 people have officially accomplished.

But a few weeks ago, over a single weekend, four climbers died on their way down from the summit of Mount Everest as the weather worsened and a traffic jam of several hundred people scrambled to conquer the world’s highest peak.

The deaths highlighted concerns about overcrowding at Everest’s highest camp, above which is an icy and treacherous terrain low on oxygen. In places, climbers can only traverse one at a time, causing serious delays at extreme altitudes, risking frostbite and the exhaustion of oxygen stores.

And just this past week, an experienced man climbing alone on the south side of Mount Hood in Oregon fell 1,000 feet to his death.