Trial Lake is one of my favorite campgrounds. Elevation is 9500 feet, so be prepared for cold nights and quick change in weather. Once when we camped, it rained, hailed, was crazy windy, and sunny, all in the same weekend.
This year because of the snow and flooding, we were there mid-July and the campground had just opened. We've stayed in site #7 (right on the water) and #1 (a double site.) Site #1 is at the bottom of a big hill which really limited where we could put our tents. There are 2 10x10 tent pads, but one of our tents is 14x14, so we had to put it in the grass and sleep on an incline. The location of the site is literally right across the road from the lake. We would just walk across with our chairs and kayaks and enjoyed the day, but it also meant that other people were parking at our site or literally walking thru the middle of the site to get to the water (nothing to do with the campground, just people's bad manners.) The water was beautiful. The site itself had a ton of bugs and small worm like bugs were falling out of the trees over the picnic tables. I like the lake, but I wouldn't stay at site #1 again.