Pasting over from my (apparently inspiring!) post on the other thread...23/771 courses played or just under 3%. I wouldn't consider Osprey Ridge a NLE course, as it's the same Fazio as before with an added par three in the middle of the back nine and the 18th changed from a long 4 to a long 3.
Several of these have closed in the last year or two...Aetna Springs, Glen Ellen (a Ron Prichard c. 2000 redo), Lakeview (after 60 years), Wolf Run, Riddell's Bay.
Alpha by state then course name:
Aetna Springs, CA. Well-documented here.
Cougar Canyon, CO. Trekked almost down to NM for this Nicklaus course, but it hasn't been open since 2014 or so.
Boca Raton Executive CC, FL. Used to play here when I was 13-14 visiting my friend who moved down. Forgettable.
Diamondback GC, FL. A Joe Lee course carved from the jungle across the street from Grenelefe. Was pretty fun, if impenetrable off the fairway.
Eagle Pines at Disney, FL. Now lays under the Four Seasons...it was pretty good if regular Dye stuff.
Grenelefe West, FL. What a strange history for this development, from it's peak in the 80s/90s, this course hosted Q School a couple times...then it had a long decline into the early 2000s when I visited. I think the other two courses are still open, but this one was the best one. I think Grenelefe still exists as a development entity, but it's changed hands several times.
Marriott Grande Pines, FL...plowed under for development c. 2015...it was pretty good, more traditionally-minded than most Orlando fare.
Sugarloaf Mountain, FL. Well-documented C&C that fell victim to the recession.
Longshadow, GA. Former Dixie Cup host, one of Mike Young's best.
Kauai Lagoons Mokihana, HI (remants still exist in the form of practice holes)...a regular, modern Nicklaus that was the relief course for it's sister. A few holes bordered the runway at Lihue airport.
Kona CC (Alii), HI. Not sure what happened here, but the Ocean Course is the only game at Kona CC today.
Wolf Run, IN. Closed after 2017 for redevelopment.
Beechtree, MD. Well documented Doak. Played it once just before it closed on a special trip, very nice place.
Colonial GC, MA. Now lies under the MarketStreet mall, had its roots in the 40s. Used to have a long par four right along 128.
Glen Ellen, MA (may re-open as 9, who knows)...Ron Prichard re-bunkered this 60s-era course...was pretty good!
Lakeview, MA. A mom-and-pop executive nine along 114 on the North Shore of Boston, it operated for 70 years before closing in 2016.
Quail Ridge, MA (the back nine was closed, 9 holes now). Ill-fated course opened just before the recession.
Winchendon School GC, MA (a Ross!). Owned by the Winchendon School, which occupies the original clubhouse, they decided in 2016 to stop paying to maintain it. Too bad, its a fun if short Ross mail-in course that is worth saving.
Tallgrass, NY. Well-documented Hanse course. I shot 68 on my only visit!
Marsh Harbour, NC. Target golf, although one of the better layouts in Myrtle at the time...at least on the Northern end.
The Pit, NC. Wild course that may one day be covered by C&C's Pinehurst #10.
Valley Forge, PA. Findlay roots I think..I played it once when I was 15, and hit a couple balls into very busy traffic.
Riddell's Bay, Bermuda. Ridiculous. In theory could re-open 9 at some point, but I believe the developers have started taking one nine apart already. Open land is at a premium in BDA, not sure why anyone let this happen.
There are some others that are certainly in limbo, and a few that have been heavily re-designed, but I did not include those above.