First of all, the heading "Reds Meadow Pack Station" is misleading. There are two businesses side by side, under the same management: One is a "resort" with about 10 cabins and a few motel units (the latter presumably lack the kitchen facilities one gets in a cabin), the other is a pack station that takes people on trail rides. Most resort guests don't ride the horses, and most trail riders don't stay at the resort. But we did both.
The 2-hour trail ride to Rainbow Falls cost $65 per person, about average for this sort of thing.
They also offer 4-hour and all-day rides. Anyway it's a good idea to go to Rainbow Falls on horseback since the 2.5 mile is steep, mostly without shade, and uphill on the way back. Our guide was very pleasant and full of information. At the falls we had a good half hour to look at it from all angles, take pictures, etc. My horse "Babe" was very easy to ride even for a beginner. I recommend this activity without hesitation.
Now for the so-called resort:
a)The good: the location is great because people who stay at the Resort are allowed to drive their cars into the Postpile Monument instead of taking the shuttle bus. So we were able to drive to all the destinations like the Ranger Station and the various trail heads without having to wait for the bus. Also the staff were friendly and knowledgeable and this made it very easy to put up with the less terrific aspects of this operation.
b)The bad: the cabins are rustic but adequate. But this is no resort: there is no nice area to relax and enjoy the scenery, there is no kids playground -- everything is quite basic. Admittedly the area was hit by a devastating storm in November of 2011 and they were still picking up the pieces. And I am sure they can't make a fortune in the short season so maybe they the economics don't allow for flower beds, picnic tables, playground, etc.
The Mule Cafe restaurant is open til 7 pm and serves the basics. I couldn't eat the potato salad which was drenched in mustard for some reason. Also there were some loud and inconsiderate people just hanging out and drinking which made our meal less than enjoyable.
c)The ugly: My wife got a case of scabies there. I presume our sheets were clean, but maybe they don't wash the blanket after every guest. Not everybody is susceptible to scabies but if you are you may want to take extra precautions.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.