One of my favorite rides of all time! But I'd rate it as difficult based on the number of problems horses have had on this trail. Slide lake is a gorgeous, scenic, interesting ride with some potentially gnarly trail hazards. More information: http://www.visitpinedale.org/explore/lakes/slide-lake The trail head is out of the Green River Lakes trail head. The trail is pretty well marked except for where it crosses the 'bog'. Most of the trails in this area alternate between soft and nice, and gnarly, punishing rocks (shoes/boots strongly recommended). For this trail, boots are pretty questionable (I've ridden it with them, but strongly prefer shoes on this trail), because of the boot-sucking bog plus the difficult footing in some of the rocky areas. The trail along Green River Lake is very beautiful, nice trotting too, but with some really huge badger (?) holes to watch out for. The trail is really good until you get to the bog (which is between 3 and 4 on this map). There is a footbridge for people, and a foot trail through the boggy area, but do NOT take this foot trail with horses. The first year we rode here, an outfitter had bogged down several horses in this area and struggled a long time to get them out. We could not find a way across the bog at this point that was passable with horses. The better trail is to go past the footbridge, where the land levels out again, you can see tracks in the grass where probably an outfitter regularly crosses the creek, and tracks in the (tall) grass across the bog. On the far side of the bog is a post, probably an old sign post, hard to see until you know it is there. Look for that, and head that direction. It was still boggy, but passable. This bog is no joke, so follow the GPS and look carefully for tracks of other horses having crossed where you want to cross. I'm guessing the bog varies by year, so use your own judgment here. It is easier to see the tracks across the bog from the original trail, before you cross the river, since you are high above it and have a good view. Spot your track before crossing the river. The river crossing is reasonably good, depending on how high the river is (2-3 feet), although it puts quite a bit of pressure on the horse, and they may tend/try to drift down stream. Stay away from the insides of the curves, though, as they have very deep pools you can easily stumble into, and my friend's horse went down over his head and swam/plunged out (everyone got drenched!). Once across the bog, the trail to the lake is a good trail, quite steep with a lot of switch backs, and a few narrow/cliffy areas. Stop at 'Fish Bowl Springs' (see above). As you get close to Slide Lake, there is one huge, rocky area, that is dangerous for horses. Just be paying attention, and go around (above) it. The main trail goes straight up a large slick rock boulder, which is not good footing for horses. There is a better horse trail that goes left/above it, avoiding the slick rock. The last mile or so up to the lake is very rocky/steep/steppy and in some places difficult to navigate. Slide Lake is beautiful. You can hike along the left side of it a long ways (cool hike), but you can't take horses, too narrow and you have to climb over a lot of boulders and stuff. There are a lot of animals, including grizzly and black bear, in this area (one followed us along this hike, use appropriate precaution). It seems there is a thunder storm every afternoon, and many trees were lightning-struck, so be aware of the weather in this area, and you'll probably need rain gear many afternoons. My GPS quit before getting to the lake, as you can see, but the trail is clear and well marked. (This means the total path is longer than indicated here.) This is not a loop, you just ride in and ride out the same way. Avoid the 'other' side of Green River Lake. It is tempting (and possible) to cross over and return on that side, and much of the trail is very soft and nice. But once you are along-side the lake, there are several extremely narrow, steep cliffy drop offs. There is so much deadfall in this area, that there is a good risk that it would block this narrow trail in ways that would be impossible to get around, and with the trail so narrow, also very difficult and dangerous to turn and go back. The trail is marked 'Not Recommended for LiveStock' on the campground side, but not the south end, so it could be easy to think it was a reasonable trail. It is NOT a good horse trail in these narrow areas, so just don't get tempted.