Check for updates to the master-list here, these are just a collection of the sites that where not down at the moment they were collected:
http://islamicbulletin.org/services/masjid.htm#mosque


---
List of mosque websites:

http://icabayarea.org/
http://www.berkeleymasjid.org/
www.brmcc.org
http://yaseen.org/
http://scmosque.org/
http://www.islamiccenterofcontracosta.com/
https://www.davismasjid.org/
http://www.fairfieldmasjid.com/
http://masjidbilal.com/
http://www.mcfolsom.com/
http://www.iseb.org/
http://www.icfbayarea.org/
http://www.ikicenter.org/
http://www.masjidfresno.org/
http://www.masjidbadr.org/
http://www.masjidmadera.com/
http://www.icomanteca.org/
http://alhilaal.org/
http://www.peninsulamuslimassociation.com/
http://www.mec1.org/
http://www.islamiccenternm.org/
https://www.masjidulwaritheen.org/
http://www.lighthousemosque.org/
http://web.stanford.edu/group/msu/cgi-bin/wordpress/
http://www.islamiccenterofpetaluma.org/
http://www.islamicbulletin.org/beliefs.html
http://is-rc.org/
http://www.ispchome.com/
http://masjidaisha.com/
http://www.masjidannur.com/
http://www.masjidassabur.org/
https://www.masjidibrahim.org/
https://www.salamcenter.org/
http://mallasite.com/ALSABEEL/
https://sbia.info/
https://sites.google.com/a/bvmcc.org/bvmcc/
http://www.svic.org/blog/
http://www.srvic.org/
http://www.mca-sfba.org/
http://www.islamicsociety-sr.org/
https://www.wvmuslim.org/
http://www.montereymosque.org/
http://www.isotracy.org/
http://www.tracyislamiccenter.org/
http://www.woodlandmosque.org/
http://www.altaqwamasjid.com/
http://www.aicpca.org/
http://www.wcismasjid.com/
http://www.coronamuslims.com/
http://isocmasjid.org/
http://www.islamsb.org/
http://www.ich-la.org/
http://www.icotv.org/
http://www.icoi.net/
http://www.muslimcsi.org/
http://masjidalnoor.org/
http://www.longbeachislamiccenter.com/
http://www.islamiccenter.com/
http://www.masjidbilalonline.com/
http://www.ocif.org/
http://www.iccv.org/
http://www.icnoho.org/
http://www.islamiccenterofventuracounty.com/
http://www.icnc.ws/
http://ranchomasjid.org/
http://islamicsocietyofcal.org/
https://icsgv.com/
http://www.icsd.org/
http://massandiego.org/
http://www.acicmasjid.org/
https://www.hudacommunitycenter.org/
http://www.masjidgibrael.org/
http://mosqueofnasreen.org/
http://www.icscv.org/demo/
http://mominlodge.com/
http://www.darulfalah.com/
http://www.alnuric.org/