Pros:
A very challenging, hilly tract of forest.
-Amenities: Concrete tees. DISCatchers, which are absolutely necessary for a course this wooded. Tee signs have number, par, and distance.
-Seclusion: Feels like a private course, other than the occasional car driving past on the two-lane rural highway.
-Elevation: Substantial elevation change comes into play frequently, a good complement to the thick woods.
-Challenge: If you're dissatisfied with the difficulty of most wooded courses, come here. It's a beast--whether in a good way or a bad way will depend on your skill level. Though mostly par 3's, Dog River requires substantial distance at times and the whole course is covered in very thick forest. I checked, and in 2019 tournament play an even par round netted a 981, which would rank it a touch harder than the gold course at WR Jackson in the 2017 Worlds, where even par was a 976.
-Shot Shaping/Gameplay: Good, even pretty great for an almost entirely par-3 course with only one type of terrain (thick woods). There is a good mix of straighter shots, pockets, gentle curves, and sharp turns. Definitely a lot of risk/reward with all the trees. The elevation will also challenge your touch, and if you fail it'll be a tricky putt. A dream course for advanced technical players.
Cons:
A tad bit rough, and make sure you know what you're getting into.
-Signage: A woods course with diverse lines + signs with no maps = huge annoyance. I think this is a course that you'll have to know well to score well.
-Difficulty: As noted above, by one metric this course is even harder than the hardest at the International Disc Golf Center. As a rec player, I got obliterated. I wouldn't recommend coming here unless you like woods courses, and probably only if you're an advanced player (or really like accumulating strokes).
-Disc Loss: Bring the bright colors. Some shots are blind and there are spots of rough that are thick, if not painful.
-Forgiveness: I don't think Dog River understands what this means. It's scramble practice heaven, because any mistake will put you in a desperate spot.
-Suspect Holes: I won't bother to enumerate which ones (check wellsbranch's review if you care), but a handful of these holes are borderline unbelievable. I think they're all birdie-able with a good putt; however, I think even pros would be playing only for a long putt (not the pin) on some.
-Benches: I don't recall seeing any benches, which is a crucial omission with the steep hills here.
Other Thoughts:
People's feelings about Dog River will vary widely. Technical advanced players could easily give it a 4.5, while bomber-type intermediates might easily give it a 0.5. I've stuck with Good, because the lines are generally plausible for an advanced player and the elevation adds excitement, but there are some wonk-a-doodle holes and the target market is really small. I'd suggest that if you dislike trees and/or you aren't a highly proficient player, you should stay away.