JIM ELSER SCANNED THE SNOWFIELDS clinging to the lower slopes of Clements Mountain in Montana’s Glacier National Park. While nearby tourists snapped pictures of soaring rock faces and searched for wildlife, Elser, an ecologist at the University of Montana and the director of the Flathead Lake Biological Station, concentrated on just one thing: finding snow algae.
Elser and his research team tramped past flourishing purple asters and yellow arnica wildflowers, gaining elevation until they crested a ridge above a small basin. Marmot chirps replaced the sound of idling car engines at the Logan Pass parking lot, which swarmed with August visitors. A soft hum came from the bulky rectangular device strapped to the back of his colleague, Joe Giersch, an aquatic entomologist at the University of Montana; the device, a light-measuring tool, was warming up in preparation for the scientists’ data collection.
Then, from roughly 100 yards away, the three scientists noticed a faint blush on the
