Pros:
The "Nut" is a well-designed challenge that is appropriate for all levels of disc golfers, except perhaps for the weak-armed beginner for whom the course could be a frustrating marathon. There is a short tee option on each hole, but the layout is still plenty challenging from the front cement pads as well. As I note below (in the "Cons" section), if I were to rate the course on its design alone - especially since I would rate 15 of the 18 holes as being well above average to excellent - it would be a "4.5" caliber course.
After a similar "look" and feel to the first three holes - a chance to warm up your arm and feel for the plastic -- holes 4 through 18 all offer something a bit different. The great diversity of holes require your full arsenal of discs and throwing techniques. To be more specific, the holes lend variety on the following spectrums:
-- Open parkland vs. Tight woods: #1, #2, #7, #13 and #16 are fairly open holes on grassy public park space with plenty of large, leafy hardwoods, with still some hazards and obstacles to either or both sides of the target driving areas as well as closer to the basket. #4, #9, #10, #11, #12, #14, #15, and #18 are all tight enough to trigger forearm tension at the tee - that is, they require a great deal of control right from the first throw.
-- Turns, Fades and Doglegs - "Left" vs. "Right" veering flight paths. Every hole requires some pre-thought at the tee about how you want to angle the disc at the point of release. The ease of your second throw (approach) or putt will depend primarily on how successfully you execute that intended flight path. None of the holes are entirely straight away in nature, and 10 have moderate to severe dogleg/fade requirements. Rewinding my mental video clip, I recall an equal number of holes - five each -- that are primarily right-to-left in orientation (10, 11, 14, end of 15, and 16) and left-to-right in orientation (2, 5, 9, 12, 17). And most of the remaining holes allow you a choice - left, right, straight, or S-curve -- in how you want to navigate tee-to-basket.
Great courses all need signature holes. At Walnut Ridge, I was particularly impressed with these holes that required a combination of length and precision: #4, #5, #9, #10, #15 and #17 (B-pin position). More details of these holes are shared in Other Comments.
Hole #18 is a great finishing hole -- especially for tournament play because there can easily be a two-stroke swing in the score between you and your competitor; a birdie is very possible (an ace not impossible), but equally possible is an errant disc that gets tree-deflected deep into the woods, leading to a bogey or even worse.
Other positives: Cement pads. The signs - when they are present (see also "Cons") - are attractive and a good basic guide to each hole's layout.
Cons:
If based only on the individual design of holes 4 through 18, I would rate Walnut Ridge a solid 4.5. What notches it down for me to a 4.1 or 4.2 rating (rounded down to a 4-star) are these nit-picky areas for improvement.
-- Missing signs! Inconsequential for repeat players who know the course, but definitely annoying to the first-time player going at it alone without a local player / guide. On the day I played, signs were missing from a few of the back tees. As noted in the "Pros," the signs that do exist are attractive and give a pretty good sense of the hole layouts.
-- Some course flow issues, especially these two long and confusing intervals (two long walks of 200 to 300 yards): from hole #3 to tee #4; hole #15 to tee #16. Getting lost is not a problem for repeat players or those tagging along with locals Either way, the length of the intervals is a bit of a negative unless, that is, you need those three or four minutes of walking to get over a poor score on the previous hole.
-- The first three holes, design-wise, are somewhat redundant (open space to left, heavy wooded area to the right) and, as a result, forgettable if you stay out of trouble. On the other hand, if you do pull it right (for RHBH throwers) into the trees or, worse yet, all the way over the ledge and down by the shores of Saylorville Lake on #3, then you will not forget these opening homes. I suppose one could argue that these three holes serve the important function of allowing your arm to warm up in time for the real test that begins in the woods on #4.
Other Thoughts:
As noted above, the following would be my vote for "signature holes." I also loved holes 11, 12, 13 and 14 and 18, so I could well imagine other players suggesting one or two of these as "signature" quality as well. Any time a DG course can claim this many memorable holes, it is deserving of its high ranking in the 4.0 to 4.5 range. Here are a few comments about the holes I rate most highly:
#4 - after a rather "open" un-shaded start on holes 1 to 3, you head into the woods on this hole; there is a distinct fairway with trees scattered along the way, particularly from around two-thirds of the way there (try to avoid the ricochets as far down the tree-lined fairway as possible)
#5 - the drive can be rather open if you choose, but if you are looking to get the first throw as close as possible, the location of the pin over the hill and down beyond a cluster of trees forces you to throw the disc in close proximity to the "Christmas tree" evergreen (typically to the right of it, unless you are a leftie with a big hyzer); a very precise "S" curve drive is required to get you within range of the well-protected basket
#9 - what a hole this is! It was unfortunate that the back tee was flooded on the day I played; long tee was flooded; but the hole was still interesting from the regular tees as you throw down a fairway well-defined by brush and trees on either side; this requires a well-controlled drive, hopefully to the left center of the fairway so that you have an open throw to the pin at the end of the long, dogleg-right fairway
#10 - the large branch overhanging the fairway (visually appealing) gives you little option but to throw a low, fast screamer off the tee; if you can get past the opening under the branch without ricochets, your 2nd to the hole is made much easier; playing for the first time, I had no idea what trouble awaited to the area on either side of the approach to the hole from around 40 yards out; the overgrown brush and leafy trees hide the fact that there is a steep drop off down into a creek bed that circles around, in a horseshoe fashion, around each side and behind the hole - beware of the discs that roll down deep into these gullies!
#15 - this is a marathon corridor hole; if you manage to not hit any trees on your first two throws, congratulations (you've experienced a minor miracle); any ricochet to the left or right on your first, second or even third throw automatically adds one stroke to your score
#17 - one of the best holes on the course I think; a unique dogleg that requires distance control off the tee; the amateur should aim for a straight throw of between 65 to 80 yards from the long tees; this will set you up to take the right-hand turn through a thick of trees to the hole. If you try to annie it (RHBH) into the opening. Good luck! Any miscalculation - short or long - means you may be adding an automatic stroke to your score.