A few I can think of suggesting that live in your area are..
Clarks Grebe.. http://www.utahbirds.org/birdsofutah/BirdsA-C/ClarksGrebe3.htm
Western Grebe.. http://sdakotabirds.com/diffids/western_clarks_grebe.htm
Red-necked grebe.. http://images.google.ca/images?svnum=10&hl=en&q=red-necked+grebe
Yellow-billed loon.. http://images.google.ca/images?svnum=10&hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=yellow-billed+loon&spell=1
Pelagic Cormorant.. http://alaska.fws.gov/fisheries/fieldoffice/juneau/birds/pc.htm
Brandt's cormorant.. http://www.bobsteelephoto.com/Species/brco.html
Double-crested Cormorant.. http://www.florida-tourism.net/florida-wildlife/bird-images/double-crested-cormorant/double-crested-cormorant-ddwr8.JPG
Other than that I cant think of anything else.. you might try going to this site with a list of birds in your area and do a image search for each aquatic bird to see if it was the one you saw.. http://www.ups.edu/x5665.xml
Good luck! I hope you identify your bird!
PS I doubt it is a common loon.. they do not have any red except for their eyes and their bills are black.. http://everyschool.org/u/shelly/egmeyer/web-based_lesson/common_loon_large.jpg