This website has reviewed the Tom Harrison Map Pack and the The John Muir Trail Atlas by Blackwoods Press. I’ve used both, both have advantages & disadvantages, and both come from small, cottage-industry, publishers.
There is a new map guide available this year, and it is from a giant in the industry: National Geographic. The cost is $14.95, plus shipping.
The guide measures 9 3/8 inches high and 4 1/4 inches wide. When open it presents itself almost as a square, at 9 3/8 by 8 1/2. It weighs in at 3 3/8 ounces and is forty-eight pages long.
Fourteen of those pages contain information other than maps. That includes a one-page primer on the trail and its history, including the comment that the trail “crosses seven high mountain passes.” It’s not clear which one of the big eight has been demoted.
Also included are pages on wilderness regulations, permits, resupply, and a twenty-one day itinerary. Nearly half of a page is devoted to “bear safety”, which might make someone (inappropriately) infer that bears are the biggest risk on the trail. Perhaps this was imported from a different guide for an area where there were grizzlies?
The twenty-one day itinerary is generally a good one, although I have two quibbles: first, the daily mileage varies widely, from as little as 4.9 miles to as much as 12.9 miles. Even in the second half of the hike, when you’ve gotten your trail-legs and are capable of higher mileage, three of the suggested days require less than ten miles of walking.
My second concern is the last day—or days. Somewhat confusingly, Day 21 starts at Crabtree Meadow and ends at Mount Whitney. Day 21a (I’m not sure how day 21a differs from day 22) runs from the summit of Whitney to Whitney Portal.
If you poll JMT enthusiasts, some will suggest stopping at Trail Camp or Outpost Camp on the way down from the summit, splitting the last eighteen miles or so (from Guitar Lake to Whitney Portal) over two days. Others will suggest camping at Guitar Lake, summiting early in the morning, and then heading down to the portal in a single day. I don’t know anyone who would recommend spending the last night at Crabtree Meadow and walking all the way out, and if the intent is to do that in two days, then it’s not really a twenty-one day itinerary.
Once you get past this front matter and into the map pages the guide really begins to shine. The maps are colorful, of a consistent scale, full of important data, and are generally up to the standard one would expect from National Geographic.
Contour lines are highly visible (the contour interval is 100 feet) and each page has a profile that includes the terrain represented on that page, as well as a bit on the page before and after. Sixty-one landmarks and waypoints are designated on the map; all appear on a two-page summary that includes lat/long and UTM coordinates. If there is a way to directly download those sixty-one points to a GPS, it wasn’t described in the guide. [Update: see link, below, in the comment section.]
Lots of helpful information is printed on the maps, like special camping or fire restrictions and dry stretches.
Those of us who like to make notes right on the map will find the waterproof paper less than optimal. Ball point ink smudges, and pencil marks are readable in good light, but are very light.
Unless you are really trying to do this hike as cheaply as possible, I would recommend buying the Harrison Mapset, the Blackwoods Press Atlas, and this product from National Geographic. All would be useful during planning, and you can decide which one you want to take with you while holding them in your hands.
Good hiking, Ray