Other reviewers gave good descriptions, so I will cover other points:
Getting there: From Oakhurst, drive North on hwy 41 to the intersection of hwy 222. Turns left, then immediately turn right and drive up hill on a narrow paved road to a signed junction for the lower campground
There are about 20 sites in this area, a few suitable for large rigs. A steel stairway is provided to get to the lodge. We stayed in this area. We were there in late March, and it was nearly empty, except for a motor home at the far end that appeared to be stored. Two other one night campers were there during our three night stay.
To reach the upper campground, continue to the lodge parking lot and turn right at the far end and continue up hill. Camping is in a circular area, with about 6 sites. One is on a slab with a large motor home, which I assume is used by the camp host during the busy season. One site was empty, (a deep site suitable for a big rig, not super level), and the remainder filled. There is an exit road at the far end, so a U-turn is not needed to leave. This campground has shade and is a little nicer in appearance.
This lodge is unusual, in that non-members are welcome. We used the self-registration at the lodge. We were not there when meals were available, but Elks lodges typically have good cafeteria-type meals, and a bar that serves drinks that are not watered down with both meals and drinks available at reasonable prices. We are Elks, and a prime reason for joining is the RV site availability at many lodges, particularly in the Western states. We have a small travel trailer, and will definitely stay again. Non-Elks fee is $25. - Jim22
They have restrooms but no showers. Lodge is only open a few times a week. - Steve A
Water pressure is very low. We had an excellent Friday night dinner for $12. The camping is kind of rough, gravel and sand and the approach road is tough and very steep but it's a good place to stay if you are visiting Yosemite. My husband said he would be there again but I'm not that sure. - kathiecarlson
If I could give this park a lower rating I would. It is an old, run down Mobil home park with some very narrow spaces. Words don't describe what a bad park this is. Don't stay there if you have a choice. - Linda Allan
We were a little apprehensive about this RV park based on some of the reviews, but we were pleasantly surprised. Yes, the sites are a little close together, but we had adequate room. There's no stream, but that's probably due to the severe drought. The sites were all shaded. The bathrooms were clean. The manager was delightful and very helpful. We were there for three nights while we visited Yosemite and would definitely stay there again. There aren't a lot of amenities except free wifi, but we found that all our needs were met. - RV Wizards
We are currently on our second night of a three night stay at High Sierra RV. Check-in yesterday was a breeze. In fact, it was probably the quickest check-in/setup we've ever had. The RV park is part permanent residents, part vacationers but the two areas are separated pretty well. The park isn't huge and there aren't a ton of sites, but honestly, it was kind of nice and it has made our stay very quiet. We are in site 42, which backs up to the river/stream and we can hear the trickle from our rig. California is in a major drought right now so there isn't much water in the stream. But, even with the drought, there is plenty of water in the swimming hole, which made my two boys happy! There is a $20 refundable key deposit for the showers, which we didn't use since we have full hookups. The laundry facility is small and there are no frills, but it's clean so there is nothing to complain about. We're rather enjoyed our stay here and would definitely come back. The folks that run the place were pleasant enough and helpful when we asked for help/recommendations. - fairestoneofall