FINDING this cache should be quite simple. REACHING it may be quite another story!
You may find that you need a 4WD vehicle, a boat, 100' of stout rope, plenty of water, bug repellent, survival equipment, a 5 day supply of food, and a good map and compass. It is HIGHLY recommended that you have someone accompany you, as teamwork is essential, and for safety reasons. You should also let someone know where you are going in case you don't return within a week's time.
Once you have found your way to the end of "drivable" road, you will then have to survey the situation, depending on the time of year and weather conditions, to decide how best to proceed, and by what method.
Be safe, have fun (?), and come back soon to tell your story of adventure and discovery!