This was a small, metal box cleverly painted so that it matches its surroundings. The container itself is quite small and contains just a waterproof logsheet which has been folded to fit and a tiny pencil.
Update: This is now a small lock & lock which is not cleverly painted, but still difficult to find. There's a fair bit of stuff packed into the little container.
The lucky person who finds it first will find a special brass tag which they can bring with them to the GAG-7 dinner and present to Keeper of Maps and Kathy for a liquid refreshment. :)
Update: Congrats to Tripper and grizzlyG on their shared FTF! Tripper received a beer at the GAG7 dinner and they both got beer-related t-shirts as souvenirs.