to add another thought. Most park rangers that I know that worked in Yosemite said...the black bears like pepper spray!
It works on Grizzly bears...but the black bears you would need one of those sprays that also has the tear gas included and might as well add the dye...that way if you were attack lol you have marked that bear with bright dye.
I carried one both times on the JMT ...but not for bears.
Just for fun...
In addition to wearing bells and carrying pepper spray while hiking in Grizzly country, it is critical that one be able to distinguish black bear scat from grizzly scat. Black bear scat is found in little black piles, about eight inches wide, along the trail. Grizzly scat is much larger, usually has little bells in it, and smells like pepper.
— Posted by The Outdoors Guy
On a more serious note however...
Interesting and informative article and comments. I spent 30 years as a national park service ranger at 8 parks, including Glacier NP in Montana where both black bears and grizzlies are native.
Similar conclusions are found in a U.S. Fish and Wildlife article “Bear Spray vs. bullets” found at http://mountain-prairie.fws.gov/species/mammals/grizzly /bear%20spray.pdf .
It is important to note that the “personal defense” pepper sprays widely sold for use against humans is NOT the same product as bear pepper spray. The “human” version is not effective against bears for many reasons, including the capacity of the canister and the distance at which the spray is delivered. Unfortunately, based on a limited, informal survey, a significant number of hikers in parks like Glacier seem to be carrying the “human” version of pepper spray, and thus have a false sense of security.
The bear pepper spray is an excellent product for self-defense, but as some previous comments have noted, the most important defense is education and good technique to minimize the risks of a bear encounter in the first place.
— Posted by Jim B