The The Dry Stone Conservancy is a non-profit organisation based in Kentucky. They are dedicated to the conservation and restoration of dry stone work all around America. I have worked with them several times and you can see some of the projects in the galleries here. Their website has some interesting information about their projects all over America.
The Dry Stone Walling Association is a charitable organisation committed to the preservation of dry stone walls throughout Great Britain and to the training of people in the craft of dry stone dyking. I have been DSWA certified since 1996.
This website contains good technical information about dry stone walling, explaining the terms and techniques used.
