If you find errors on the Tom Harrison maps please share them with Tom. He will try to verify and incorporate the changes in the next edition.
The only printed option to the Tom Harrison map is the USFS map/guide:
A digital verion of this map is also available:
When the Mill Creek Visitor Center reopens you’ll be able to purchase the printed USFS map there.
One additional option, covering only the eastern side of the mountain, is the National Geographic Pacific Crest Trail map guide 1011. It’s available as a printed booklet and digitally.
Measuring distances with good accuracy along a winding trail in the mountains requires using a surveyors wheel. GPS is unreliable due to blockage of the horizon and tree cover. Elevations measured with GPS are even less reliable except perhaps at the top of a ridge or mountain (with good views of the horizon in most directions).
Digital maps have no better accuracy than printed maps, are usually based on the USGS maps, and sometimes are extremely out of date. A $100 Garmin Topo digital trail map that I recently purchased to use with my Garmin GPS for a Grand Canyon backpack lacked the connecting trail to the campground that we were staying at on the Colorado River – a trail that had been in existence for at least a couple of decades. The trail, and the campground, did appear on most printed maps.