Leupold has published images of a Weatherby Mark V rifle found in Idaho wilderness after 11 years of being lost. The rifle is equipped with a Leupold scope and the company claims that it is still fog-free and fully functional. The man who found this rifle brought it to a local sporting goods store, where the store owner identified it as his rifle which he lost 11 years ago during a hunting trip.
As you can see the wooden and steel parts show what time and weather can do. However, the scope looks almost as good as if it was newly installed on the rifle. The most interesting part of this story is that the scope remained sealed. Other than that, it could be expected that there would be no corrosion signs on the scope. Wood and steel are materials sensitive to moisture. So sooner or later the finish will be gone and they will start corroding. However, the major parts of the scope are made of aluminum and glass or polymer materials, which are pretty much resistant to moisture. Even rifle scopes dug out from WW2 battlefields usually have intact glasses despite the broken seal.
These kind of stories are perhaps excellent marketing tools or proof of the quality for hunting scope manufacturers. A couple of years ago Zeiss published a similar story with their scope.
It would be interesting to see what would happen to a rifle with a stainless steel barreled action and polymer stock. Possibly it would stay in almost original condition if left in the woods for a decade.