Everywhere is walking distance if you have the time.
Cell phones can not receive signals in many mountainous and wilderness areas.
The mountains often block signals. While outside mountain regions, cell phones can be a great help in an emergency, you should never depend on them for help in a hiking emergency in the mountains or wilderness areas. If you are able to make contact with the authorities you will then need to identify yourself, identify as specifically as you can where you believe you are - including which mountain and trail you are on, the nature of the emergency,and your cell phone number. Be as specific as possible and remember it may be hours before rescuers will reach you.
Remember: technology is NEVER a substitute for knowledge and experience. You must know how to rescue yourself.
More and more hikers are carrying a GPS - Global Positioning System - with them. A GPS can help you stay on course as you hike to your destination. It can also track where you've been, how far you've gone, and tally altitude gained and lost.
But like all technological tools, it can help you only if you know how to use it - and you must be prepared if it fails to work when you're on the trail. (Always carry spare batteries with you.) Never rely solely on technology. Know how to navigate without it, and how to reorient yourself if you become lost. A GPS works like a compass: best with a map.
If you do carry a GPS, before starting a hike on a new trail, download key waypoints to the GPS, and use them to plan your route. During the hike you can use the route to estimate distance and travel time. Always have a compass as a backup.
Personal Locator Beacons
One-way personal safety communications beacons are available for search and rescue use on land in the United States. These pocket-sized devices, called Personal Locator Beacons (PLB), are unique in that they allow the advantage of alerting rescue personnel about an emergency—providing a location of the emergency anywhere on Earth at the same time. When activated, the PLB works in the same way as an Emergency Locator Transmitter (ELT) on an aircraft. The PLB transmits a continuous distress signal to orbiting satellites, which then sends the signal for processing to a federal government ground station monitoring for distress signals. The satellites are able to relay the location of the distress signal so that Search and Rescue authorities will be able to locate the signal location on the ground. This information, combined with the unit’s registration information, is forwarded to the appropriate Search and Rescue authorities that then carry out the rescue mission.
Some PLBs have GPS technology built within them or can have a GPS attached to them so that when the distress signal is sent to satellites it gives a more accurate location to the authorities. Without a GPS system accuracy is within 3 miles. With a GPS system accuracy can be within 200 feet. Due to a PLB being a one-way communicator, they have the disadvantage of not allowing authorities to communicate back to the PLB with the exact nature of the emergency.
For a PLB to work at its most optimal performance, registration is required with the NOAA (National Oceanic and Atmospheric Administration) by the owner. Upon receipt of a PLB alert, the Search and Rescue authorities will first check that the registered owner of the beacon hasn’t accidentally activated it. Then they will try to confirm the approximate location before launching a rescue mission. This is another reason to leave your plans with someone at home. Also, don’t lend your PLB to anyone unless you know his or her plans, since you will be the one contacted if it’s activated.
It is very important to remember that the purpose of a PLB is to allow someone to signal a distress to rescue authorities at times of grave and immediate danger. The signal from a PLB is regarded as a sign that life is at risk and will be given an appropriate response by SAR authorities. It is the responsibility of the PLB owner to ensure that it is not activated unintentionally, or for a situation that does not justify its use. The use of a PLB should not detract from effective individual preparation. Therefore, make sure you are adequately prepared to survive as a Search and Rescue response is not always instantaneous. Also, if another means of communication is available, for example a cellular telephone, then this should be used in preference to a beacon. Cellular telephones can have the advantage of allowing authorities to speak to the individual to determine the type of distress and determine the appropriate response.
Prior to taking a PLB on a hike, make sure to test the PLB as recommended by the manufacturer, ensure the PLB is registered with NOAA, check the battery end-of-life date, and make sure you know how to activate and position it in case of an emergency.
In the end, it's about common sense
Common sense and good judgment must be exercised before a PLB is activated. As with any technology a PLB does not replace your responsibility of being properly prepared and educated before you get in a distress situation. Proper planning and emergency preparations are essential. You should make every effort to rescue yourself, including using other forms of communication or location gathering. Even with a PLB it can take many hours before a rescue team can reach you. Only utilize a PLB for true life-threatening emergencies. A PLB is not an excuse for reckless behavior, and consequences will result, if a PLB is misused.