The following list of western grottos is dynamically generated directly from the NSS database.  Only grottos with web sites are listed.  If you see errors or omissions in this list, contact the NSS to have it corrected.
Arizona Grottos
Central Arizona Grotto http://www.caves.org/grotto/cag2/
Escabrosa Grotto http://www.escabrosa.org/
Northern Arizona Grotto http://www.caves.org/grotto/nag/
Southern Arizona http://www.sagrotto.org
California Grottos
Desert Dog Troglodytes http://www.desertdogs.org/
Diablo Grotto http://www.caves.org/grotto/diablo/
Mother Lode Grotto http://www.motherlodegrotto.org
San Diego Grotto http://www.sdgrotto.com/
San Francisco Bay Chapter of NSS http://www.caves.org/grotto/sfbc/
Shasta Area Grotto http://www.caves.org/grotto/sag
Southern California Grotto http://www.SouthernCaliforniaGrotto.com
Stanislaus Speleo. Assn. http://www.stanislausgrotto.org
Colorado Grottos
Colorado Grotto http://www.caves.org/grotto/colorado/
Colorado Western Slope Grotto http://www.coloradowesternslopegrotto.org
Front Range Grotto http://www.frontrangegrotto.org
Northern Colorado Grotto http://www.northerncoloradogrotto.com
Red Canyon Grotto http://www.redcanyongrotto.org
Southern Colorado Mountain http://www.socomogro.org
Timberline Grotto http://www.caves.org/grotto/timberline/index.htm
Idaho Grottos
Gem State Grotto http://www.gemstategrotto.org/index.html
Silver Sage Grotto http://www.caves.org/grotto/ssg/
Montana Grottos
Northern Rocky Mountain Grotto http://www.caves.org/grotto/nrmg/
Nevada Grottos
Northern Nevada Grotto http://groups.yahoo.com/group/NNVGrotto/
New Mexico Grottos
New Mexico Tech Student Grotto http://infohost.nmt.edu/~nmtcaver/index.htm
Pajarito Grotto http://www.pajaritogrotto.org/
Pecos Valley Grotto http://www.caves.org/grotto/pecosvalleygrotto/
Sandia Grotto http://www.sandiagrotto.org
Oregon Grottos
Oregon Grotto http://www.oregongrotto.com
Oregon High Desert Grotto http://www.ohdgrotto.com
Willamette Valley Grotto http://www.caves.org/grotto/wvg/index.htm
Utah Grottos
Salt Lake Grotto http://www.caves.org/grotto/slgrotto
Timpanogos Grotto http://www.caves.org/grotto/timpgrotto/
Wasatch Grotto http://www.caves.org/grotto/wasatch/
Washington Grottos
Cascade Grotto http://www.cascadegrotto.org
Wyoming Grottos
Hole-in-the-Wall Grotto http://holeinthewallgrotto.com
Thunder Basin Grotto http://www.orgsites.com/wy/tbgrotto/index.html