The course is well kept on holes 1-8, 15-18. The grass is thick and green and the trees provide a good amount of shade and lines.
The lines on the original 12 holes are nice with just the right amount of trees to make you have to shape shots.
There are a few low ceiling shots as well.
Many of the holes are reachable on the original 12 so this is a nice beginner to intermediate level course.
There are 2 different layouts set up in UDisc, so if you want to play the "grass 12" holes or the full 18 you can.

Holes 9-14 lack variety. You are basically throwing in a scrub brush area with maybe 2 trees total. At least there was a bit of elevation to make up for the lack of trees. A nice up hill and a couple of down hill throwing holes.
Tee areas on the above mentioned holes are rutting and over time footing in these area will be an issue.
Signs are just posts in the course with the Hole numbers on them, so if you like to know the distance, etc., you will need to use a scoring app.

This course has been expanded to 18 holes. While it is nice to have a full 18, this course should've remained a 12 hole course. The original 12 holes have good lines with a nice mix of distances. The additional 6 holes are repetitive and there isn't much variety.
Now with that said are they terrible holes? No. You can only use what is available. The terrain on the extra 6 holes isn't as good as the other 12 holes. I did like the fact that Hole 11-13 used the present elevation to make those holes more challenging. Maybe over time with the planting of some grass and a few trees these holes could be improved.
This still is a good course and one of the better options in the area. It's better than a 2.5 but since I can't give it a 2.75, I will settle for a 3.0 rating.
If you are in the area and need to play some dam disc golf then give McNary a try.

-beautiful location with the dam right there
-nice short green grass for 12 of the 18 holes
-good baskets and wood tee markers at each hole
-great course map at hole one
-about half the tee pads are turf
-most holes allow for a forehand or backhand drive
-good variety of distances and even a couple downhill tosses
-not a busy course
-lots of parking available

-lack of signs to find the next basket (had to double check with online map)
-not all the tee pads are turf
-several longish walks to the next tee pad

McNary dam is a very nice little course. For the rec players, I would recommend playing holes 1-8, turning around and playing holes 15-18. They are pretty, fair, and not too demanding.
Holes 9-14 however are not for the weak at heart- especially if you decide to play when it's sunny and 96 out. What was I thinking? All of a sudden you're in a desert which reminded me of the desert holes at Pendleton Community Park.. only not as hilly. Luckily they still provide a couple nice downhill tosses. Finish up the the final four holes back on short grass and then enjoy the dam!
There is a really cool fish observatory thing by the hole 15 tee pad- my kids loved watching through the windows and seeing fish swimming through the fish ladder on their way around the dam.
I will play again next time I'm around!

Holes are well marked and easy to find. Map at the start really helps. Pleasant, manicured lawn for most of the course. A few trees here and there added a nice challenge.

Part of the back nine gets a little weedy. If they'd more frequently or landscape, that would make it all very nice. In spite of that, the elevation changes on that part of the course are a nice change.

I really liked this course because I could find each of the holes easily the first time I played it.

The course built by the Corps of Engineers sits in a little green manicured park right beside the McNary Dam. The sound of the water is always with you as well as different looks of the engineering features of the dam itself. It's interesting and you can always take the tour if you're interested.

The course is pretty straight forward with the first three holes playing out, then # 4 starting back. Then a walk across the parking lot to #'s 6-9.

There is a small kiosk at the beginning with a course map and a booklet for comments and info on lost discs. As I was looking at the course map, a dam employee asked me if I needed a course map and scorecard and proceeded to go inside and came out and handed me a very nice little postcard sized map on one side and scorecard on the other.

The tee signs are simple with just the hole #. There are no tee pads, just barely visible worn spots in the grass.

It's a short recreational type course throwing through and oftentimes under the trees. Often a roller is the preferred shot off the tee. The baskets are brand new and there are ACES to be had here.

There were a couple of holes where a wildly errant shot could end up over the fenced area like on 1,2 and # 8.

Previous reviewer mentions cannon fire? I thought maybe fishermen were using dynamite to fish with. Or maybe the Oregon folks were shooting across the river at the Washington troops. Some kind of civil war maybe? There was constant booming noises. It was kinda disconcerting at times but then you get used to it.

This is a nice little recreational course. The corps has done a very commendable job here putting in this course. I'd like to see something more done with the tee pads but other than that, it's first class all the way and a fun little throw.

-Well manicured course (12of18).
-Easy to navigate
-Course Map w/scorecards(sometimes)
-Veiw of the Dam/spillway, fish ladder viewing.
-Restrooms
-Turf pads (about 1/2 have them right now)
-Not busy
-Plenty of parking

-Picnic tables close to baskets.
-Fenced/UnRetrievable areas (holes 1,15,16).
-Other users of the park.
-Cannon fire
-Wind
-Thorns and dust on the hillside holes

Nice little course right off of I-82. Playing on green mowed grass is great when the sun is shining. The stand out hole for me was #7 where the fairway gets skinnier as you get closer to the basket (surrounded by pavement). The fence along the right side of hole 1 is a disc eater & you will have to call security for your disc if you go over the barbed wire top. There is cannon fire going off consistently to scare sealions & birds & it can be distracting to someone trying to putt. All holes have some kind of tree in the fairway to make for interesting shots. The park wasn't too busy the day I was there, but still found myself waiting a few times for people to pass & one lady playing w/her dog finally moved far enough away from the basket for me to throw (though I still threw short just in case). The course is split into 2 by the parking lot so you could just play 4 or 5 holes if you just wanted a break from driving, but still wanted to make good time on your trip.

2017 Update: They redesigned the front 5 to make it a little more friendly to other park users and the fence out of play (mostly).
They added on 9 more holes to get 18. 6 of these new holes are off the nice mowed grass and go up the dry dusty hill; So 3 of the new holes are a nice park setting like the rest, but the 6 on the hill are like a different course. I commend them for getting an 18 hole course and using the hill for some shot variety, but it's too bad they couldn't make those holes as nice as the rest. Maybe I'm a little bitter because a got a thorn in my throwing finger when I picked up my disc in the fairway of one of these holes.