The second volume of a new "Caves of Thailand", compiled by Martin Ellis, has been published covering the northern provinces. 

This volume has over 1,150 caves, rock shelters, stream sinks, resurgences and other sites which may be of speleological interest from the provinces of Chiang Mai, Chiang Rai, Lampang, Lamphun, Mae Hong Son, Nan, Phayao, Phrae, Sukhothai and Uttaradit. This region has Thailand's deepest caves and many of the longest caves.

This 491 page, A4 book also includes a brief caving history of  the region, 233 surveys and a bibliography with over 500 references. 

It is available from print-on-demand publisher Lulu at http://www.lulu.com/shop/martin-ellis/the-caves-of-northern-thailand/paperback/product-23404834.html for £21.88 plus postage and packing.