We have a house on a steep slope. Firewood is delivered at ground level and fireplace is 3 stories up.
I can't think of a less demanding traveler than firewood. Building an elevator for people would be a huge undertaking, with regulatory oversight and inspections and whole 9 yards but firewood? Perhaps some kind of a winch or a pulley system with a bucket might do the work just fine. Sort of like a cable car type of situation. Many, many years ago I had to deal with the situation where stone needed to be delivered uphill and over some distance, MacGyver - style. Ended up with a cable strung between two trees, a pulley, a bucket and another piece of rope to pull on it, unload, then let go so it returns downhill.
In your case you would want something more permanent of course. Very hard to tell what would be the solution in your case without knowing much about the property. Perhaps you can post some pictures? Click on the "image" button in the comment form, it will let you upload pictures.
Consider a gas fireplace....