River Crossings: Few of Yellowstone National Park's rivers or streams have bridges, and many are not fordable until July or later. Even in the late summer, water levels can rise quickly after rainstorms. The water is often cold, fast-flowing, and dangerous when more than thigh-deep. Trying to ford deep, swift water has resulted in injury, loss of gear, and death. Before beginning a trip, check a map for stream crossings and current ford conditions at a ranger station.

Before crossing, seal important items such as cameras in plastic bags and put all personal gear inside a pack. Do not ford barefooted and use a long, sturdy stick for balance. If in a group, hold hands or interlock arms while crossing. Search up and downstream to find the safest place to ford, as it may not be exactly at the trail/river junction. Unfasten the waist and chest straps of the pack in order to get out of it quickly in case of falling. When crossing, look ahead to the opposite bank rather than looking at the water.

Many warm sunny days turn abruptly into fierce stormy afternoons. Strong, gusty south to southwest winds are common each afternoon in Yellowstone. What can follow is sudden wind, rain, and lightning storms. When boating or hiking on a ridge and a storm approaches, leave the water, ridges, shores and open places. Thick forests of equal height offer better protection than meadows.

Backpackers to Yellowstone may be surprised to experience winter-like weather any time of the year. Rain, wind, sleet and snow can be deadly if proper precautions are not taken. Always bring rain gear and extra clothes for warmth. Depending on elevation, night-time temperatures can drop to 20 to 40 degrees F.

Hypothermia is generally brought on by exposure to cold. The windy, often wet, condtions of high elevations can produce hypothermia at temperatures as warm as 50 degrees F (10 degrees C).

Preparation is the best prevention for hypothermia. Carry adequate equipment for rapid weather changes. Always include rain gear, extra clothing for layers, a hat, and gloves.

Signs of hypothermia:

Drowsiness
Loss of judgement or coordination
Reduced dexterity
Slurred speech
Uncontrolled shivering

If these signs appear, begin immediate treatment. Eliminate exposure to cold and wet conditions, move out of the wind, add layers of warm, dry clothing, and begin to rewarm by administering warm, non-alcoholic liquids.

• Use portable stoves - avoid having wood fires
• Build fires only in established fire rings at campsites that permit wood fires
• Use only dead and downed wood for fires
• Do not remove branches or bark from any dead or living standing tree
• Make certain the fire is cold before leaving site
• Where it is legal to build a fire, keep it small
• Use only small sticks and branches as these burn more completely, provide a bed of clean hot coals for cooking and do not result in partially-burned or smoldering logs