WiFi tends to get a bit overloaded and is available only in the central "lounge" area. If you get near a window within one or two rooms of the lounge, you can sometimes manage a 1-bar wifi connection from your room, but it is very slow and intermittent when it works. In the lounge itself, it is rather consistent but very slow from the overload of simultaneous users and limited bandwidth - but... it is *free* and accessible, so under those conditions and limited cell/data service otherwise, it is a very welcome amenity. Having A/C would be a great addition to the rooms/comfort, but I've learned to just bring along a box fan for the window after my first visit. Seasonal rates vary substantially.
Very clean and pleasant. Convenience of the property's location is exceptional and the lodging options within the Parks are very few. I've been to John Muir lodge several times over the years and enjoyed it each time.