I debated putting this in safety, or beginner, subforum. I think it's more general.

I have read on a number of backpacking forums that people think their cell phone will provide location in the backcountry even if there is no coverage to make calls.

The short answer to the question is "not really."

The long answer involves lots of techno-speak about the progression of cell technology, FCC mandates for providers to obtain lat/long coordinates of the cell user (this is still not possible in some areas), and the kind of phone you have.

Cell phones, when on, typically ping every thirty seconds. (A ping is a request for connection that verifies a connection is possible - it's a network test. Why your cell phone knows there is no network available.) Records of pings are only kept for 24 hours. Unless you text or make a call - those are permanent records.

If the cell phone is within range of a tower, and that tower has not yet been upgraded or is communicating with an older phone lacking appropriate tech, the cell company may get information on the approximate area the cell phone is in. Imagine a pie cut into thirds. This will give them an indicator of which third of the pie you are in. Not a specific location. Narrows a search down, but if you are within range of the tower you should be able to call out.

If the tech at hand has been upgraded to more recent FCC requirements, the cell company may be able to get a lat/long coordinate for the cell phone. This is also going to happen when the cell is within range of a tower.

Any position a SAR team receives is considered the last good fix - subjects may still be moving at a rate of 2 mph in any direction, after all. Direction of travel can only be ascertained if another tower connects with the cell phone.

Some areas have a multiplicity of towers from varying providers, which leads to a multiplicity of paperwork and calls to get fixes from any of them. This will slow progress in obtaining useful information. Even with one provider unless the agency requesting information has an established relationship with the provider, it's difficult, slow, even impossible to obtain location information.

In mountainous/wilderness or rural areas, cell towers are frequently along roads - this worsens accuracy with location tech in cell phones. Optimal configuration of towers for accuracy is to have towers arranged so that cells overlap or abut each other closely - towers strung out all in a row are less accurate.

In short, there are too many variables to make cell phones a dependable means for search/law enforcement agencies to locate a subject. Plus, the cell phone needs to be in range of towers. In places like the central Sierra, you leave the towers far behind. Unless you are in Yosemite where there are towers in the valley and in Tuolumne Meadows.

This information is loosely summarized from information provided by resources within my reach by Search and Rescue. Anyone can find specifics in a variety of sources; the one in front of me at this time is an appendice in Lost Person Behavior, one of the primary resources for SAR persons.

We have had one search this year where the subject was in range of a tower. We spoke to the subject on the phone, advised them to build a fire, and our team walked in the dark up the hill to them, to guide them back to the trail and out of the wilderness. Obviously they were not far out. This was far more expedient than all the rigmarole necessary to pull location information from the provider.