There is a wealth of information on Champ located on the www.LCLT.org website. Here is a sample of their sightings list.

How many reported sightings of Champ
have there been?
Indeed, there have been over 300
reported sightings in the last 100 years. Here are a few
of the highlights:

• 1819: Bulwagga Bay, Port Henry, NY
• 1871: Horseshoe Bay, riders of the
  steamship Curlew claimed to see a head and long neck that
  created quite a wake.
• 1870: Charlotte, Vermont, a full
  steamboat spotted Champ
• 1873: Dresden, New York, another
  steamboat full spotted Champ
• 1945: In the middle of the lake the
  creature was spotted by the famous S.S. Ticonderoga
• 1954: A 14 inch reptile was trapped
  in Shelburne Bay, possibly a baby…
• 1977: The Mansi photograph was taken
  by Sandra Mansi, a tourist from Connecticut, with her Kodak
  Instamatic, of what she called a dinosaur. This has become
  the most famous piece of evidence—featured nationally
  in Time Magazine and the New York Times among others.
• 1984: Off Appletree Point, Vermont.
  86 passengers aboard the Ethan Allen spotted 3 to 5 “humps” which
  disappeared after about 3 minutes due to the approach of
  a speed boat.
• 1993: Button Bay State Park, Ferrisburgh,
  Vermont. A baby Champ reportedly swam between two women
  bathers.
• 1995: Dennis Hall of Champ Quest
  recorded Champ on video.