Pros:
Three island crossing is in a state park. Pulling up there is a little booth where you pay. They have course maps here and all sorts of other information about the area including about the Lewis and Clark trail. The lady I ran into working the booth/shack was extremely kind and full of energy which was a positive start to the day.
The course starts out winding its way back and forth across a picnic area with lush green grass. From here the course takes off in another direction and loops back towards the park style grass section towards the end. The middle of the course is dry, has junipers and other bushes guarding against going off online and punishing you if you end up in these bushes.
Navigation is fairly simple and the places where it's not they have next tee signs by the basket. Tee signs show basic information including distance, par, etc. Concrete tee pads are level and also wide and long enough to accommodate most throws. Older generation DGA baskets are all in working order and catch well, all double chains. Because you're in the picnic area for roughly half the course you also have access to the restroom and benches if you so need them.
Most of the distances here fall within 200-350 feet and the fairways range from somewhat open to low ceiling but never get wide open or super wooded. Mostly this course will challenge the intermediate players who have been playing a while and also teach the new players they have a lot to learn and have some field practice to work on things. Aside from the grass holes which are fairly forgiving even if you don't clear the low ceiling of branches or hit the tree itself the middle of the course will punish you offline. The fairways are mowed but also kind of 'wild' is the best way to describe it. The fairways are well defined by the bushes.
The Snake River is never too far off and even hole 17 tees off at its shores. There are a few holes here like 15 and 16 where too much distance will send you into the river so something to look out for. The beauty of the Snake and this park as well as the history are worth it enough to come out here.
Cons:
Although navigation is easy it may require a few walks up fairways to find basket before throwing your shot if you're going for the first time. Some of these baskets are blind shots is what I'm saying and where you think the basket may be could be totally off.
If you have really bad accuracy or shank one super nasty it is a challenge to go through some of this bush as it's thick, prickly, pointy, thorny, etc, you get the idea. I could also see spiders or perhaps even snakes laying low in the hot sun under all of this so even more good news.
The park style beginning and ending of the course play through the picnic area and on a nice day, especially the weekend there are going to be people camped in the middle of fairways. We found this to be true on a few holes and the people there seemed well aware they were in a disc golf fairway and were kind enough to move away so we could throw.
Other Thoughts:
I really liked the disc golf and loved the beauty of the area. I recommend checking out the visitors center if you're interested in the history of the Oregon trail that ran right through this area. Try not to get dysentery and die.