This is some party knowledge now:
There is a cool, real life description how to work with incomplete and even totally wrong maps and still reach your goal. The description of Maurice Herzog of the first conquest of an 8000m peak in the himalayas in 1950: “Annapurna – Maurice Herzog E.P. Dutton & Co. Inc. New York, 1953”. (Wikipedia article for those not intersted in reading 300+ pages from the 1950’s). The map he iteratively improved was still in use until late 1990’s. I still own a copy. Google Maps destroyed all illusion there. 6000m peaks were only guessed in the 1950 – not so important – until you had an unexpected one in your path. Some, nobody bothered to correct. If you hiked the Annapurna Circuit before lets say 2000, you will have used it at some point.