From the U.S. Fish and Wildlife Service's online digital media library.
Check http://images.fws.gov/ for higher quality version.

Metadata
Title: Alligator Snapping Turtle
Alternative Title: (none)
Creator: Stolz, Gary M.
Source: WO8475-002
Publisher: U.S. Fish and Wildlife Service
Contributor: DIVISION OF PUBLIC AFFAIRS
Language: EN - ENGLISH
Rights: (public domain)
Audience: (general)
Subject: Animals, Louisiana, Reptiles, Wildlife
Date Issued: October 31 2001