The organizations listed below are well established and regularly offer tours. There are lesser–known companies that offer trips to volcanoes and often advertise in magazines that cater to adventure and natural history, such as National Geographic Traveler, Outside, and Natural History. When shopping for a tour, beware of small–budget companies that are likely to cancel tours at the last minute if not enough people sign up. Ask what their track record is, whether cancellation is a possibility, and when you would know for sure. If your plans are flexible and you want to go on a true adventure, seek out volcano enthusiasts who will offer small expeditions to farflung volcanoes almost at cost, and are very clear about the possibility of cancellation. They usually advertise through their own web sites and the volcanologists's email network VOLCANO listserv (see Appendix I). Another alternative, if you can stay in the same place a couple of months, is to volunteer at a National Park or volcano observatory – check their websites for opportunities or write them a letter explaining your skills and availability.

Geological Society of America. This is the major US geological society and their GeoVentures department regularly runs a variety of field trips of geological interest. Most of their destinations are in the US, but have included Iceland and other volcanic locations. Non–members may join trips depending on availability. Further information from: Geological Society of America Geo Ventures, P.O. Box 9140, Boulder, CO 80301, USA (http://www.geosociety.org/)