The Utah Geological Survey has a good supply of Maps and data available online and some online maps. They also have an online Blog.

The GIS data is a fairly complete package–the sample I downloaded included .pdfs, shapefiles, layer files, images and ArcMap project (.MXD) files used to generate the .pdfs.  File sizes are larger because of the completeness.  Feature classes have a moderate level of attribution.

The highlight, however, are the sample Keyhole Markup (KMZ) files of the of the St. George 30′ x 60′ quadrangle that can be viewed in Google Earth.  Too cool.