About the Container
You are looking for a camouflaged pill bottle attached to a tree branch. There is room for small travel bugs and trade items. Please bring your own pen.
About the Location
You'll have to hike into this area using the trails that run parallel to the river. The container is hidden in a tree about ten feet above the ground. It will be a little more difficult than climbing a ladder but still very manageable for an average person. The container will be findable in winter but use common sense if the conditions are snowy or icy.
You will be pretty far away from the trail, so anyone passing by won't be able to see exactly what you're doing but it will be obvious from a distance that you're climbing a tree. Try to climb casually, I guess. As always, should you be caught, the Secretary will disavow any knowledge of your actions.
About the Spy Gear
Air ducts are not technically "gear" but they're such a staple of spy fiction that we could call them a tool of the trade. James Bond used air ducts to sneak around in the 1962 film, Dr. No. Ethan Hunt used them to break into a high-security vault in the 1996 film Mission: Impossible. In real life, air ducts usually have sharp screws on the inside, which is something you don't see in the movies.