Ice bridge / snow bridge

Snow and ice bridges form when accumulation spans across gaps such as streams, small ravines, or spaces between rocks. To a hiker on the surface, this can look like a continuous snowy tread, even though there may be a hollow space beneath. In some cases, the bridge is strong enough to support weight; in others, it may be weakened by meltwater, warmth, or thin coverage.

In long-distance hiking, snow bridges are occasionally encountered in early-season or shoulder-season conditions on routes that cross streams or depressions still partially covered by snow. The main concern is unpredictability. A snow bridge that looks solid from above may have hollow sections or thin edges that give way under concentrated load.

Recognizing potential snow bridges involves paying attention to terrain shape, sound, and surface characteristics. Changes in snow texture, subtle depressions, or audible hollows can signal that voids are present underneath. Hikers often adopt conservative choices around suspected bridges, such as rerouting, probing carefully, or avoiding a crossing when uncertainty is high.

Because conditions can change dramatically over short timeframes, experience and local knowledge are important for interpreting snow bridges. In many thru-hiking situations, route timing and alternate options are used to reduce encounters with these features.