When deciding what group(s) to give your hard earned conservation dollars to, it is advisable to learn as much as possible about those organizations prior to making monetary donations.
Listed below are three links that should be examined fully before making donations:
http://foundationcenter.org/pnd/news/st ... d=36500021
http://www.nationalcenter.org/dos7128.htm
http://www.undueinfluence.com/nature_conservancy.htm
My personal unsolicited and blatant suggestion is to donate to Southeastern Cave Conservation Inc. (SCCI), and/or The National Speleological Society (NSS). The SCCI will use the money very wisely to purchase or lease caves or acreage that contains caves and will make such acquisitions available to cavers while promoting conservation. The NSS is in great need of money to promote safe caving practices, promote conservation, research projects, expeditions and a whole lot more.