Spring
Each season has its outdoor hazards. Spring in the Sierra Nevada can be like winter; deep snows can still be found at high elevations, even when there's no snow in the valleys below. Avalanche danger may still exist. Hypothermia can be an issue year-round, especially if you do not have warm, waterproof clothing.

Here are some hazards you may encounter in spring.

Water crossings: In spring and after heavy rains, streams can change from trickles to torrents, making crossings difficult. If you decide to ford a stream, be extremely careful. Keeping your boots on will give you better footing and prevent your feet from going numb from the cold water. Unbuckle your pack's waistbelt before starting. Use common sense and, if in doubt, don't cross. A stream that is easily crossed in the morning may be hazardous or impossible in the afternoon as snow melt or rains raise water levels.

Avalanche: Avalanche hazard can extend into spring, particularly in years of heavy snow. Debris from winter and spring avalanches can also block trails.

Snow hazards: Snow slopes at higher elevations can become very icy in the spring .. ice axes may be desireable. Weak snow bridges across streams can collapse under your weight .. be cautious. As rocks warm up the snow close to the rock melts, leaving gaps between the snow and the rock that you can fall into. Be cautious when traversing between rocks and snow. Ice on lakes is not safe to walk on.

Bugs: The small fly, often referred to as gnats, and mosquito season usually runs from late spring to early summer. The gnats tend to stay at lower elevations while the mosquitos move up the mountains as the snow melts and plants come to life. A good insect repellent will help keep the worst of the biters away. (Some people claim that eating raw garlic will also do the trick!) A head net can be welcome protection. In years of heavy snowfall the mosquito season can last late into summer.

Lyme disease, which is transported by ticks, has been reported in California. It is a low to moderate risk in the Eastern Sierra. A good insect repellent will help repel ticks, and the threat of disease can be minimized by quick removal of any attached ticks. A daily inspection is a good habit when in tick country. Click here for more information about Lyme disease.