Books have been written about the thousands (or tens or hundreds of thousands) of frozen animals that have been found in the North. Supposedly mammoth meat was served at a scientific banquet. This is held out as evidence for some sort of great catastrophe, which quick froze them all, with fresh buttercups still on their lips. Some Creationists use this claim to cast doubt on uniformitarian science.
Less than fifty frozen animals have been found. Most were pretty decayed, and only a few were whole. They all have different carbon dates, spread across the last 50,000 years. These are unrelated deaths that happened to result in burials.
Basically, this is a story which grew in the telling. People who go back to the original articles, written by actual discoverers, find no support for the wild claims.
For example, the Berezovka mammoth broke bones when a cliff gave way. The landslide buried it, and the animal suffocated, and was later covered by river mud. When it was found, even the frozen ground around it had a putrid odor: the discoverer said (in Russian): 'only dogs showed any appetite for [the flesh]...the stench [of decay]...was unbearable.'
Quick freezing isn't needed to preserve vegetation. For example, unfrozen, preserved plant materials have been found associated with the skeletons of mastodons in bogs in Ohio, New York, and New Jersey. Notice I said "skeleton". The meat was gone, but the anoxic (oxygen-free) conditions still preserved the contents of the gut.
For more information:
the Mammoth FAQ
Frozen Fauna of the Mammoth Steppe: The Story of Blue Babe, R.D. Guthrie, University of Chicago Press 1990, 323pp., ISBN 0-226-31122-8
Mammoths, Lister, A., and Bahn, P., Macmillan, New York 1994 168 pp.
On the Track of Ice Age Mammals, A.J. Sutcliffe, Harvard University Press 1985 224pp., ISBN 0-674-63777-1
Farrand, Wm. R. Science 133:729-735 (17 March 1961)
How to Deep Freeze a Mammoth, Bjorn Kurten, Columbia University Press, New York, New York 1986