A bunch of us landed gliders on Troy Lake in 1987 while flying in a competition. There was no runway marking, PSP, or anything like that anywhere I saw. I've been to Broadwell Lake north of Ludlow many years ago by car, nothing there but an abandoned raised railroad berm.
The East and West Superior dry lakes northwest of Barstow were desolate and billiard table smooth, but again that was 1986 or 87. Just to the north of the Superior dry Lakes is a place I call Phantom Acres, a full size dirt replica of a forward airbase, complete with a long dirt runway and several F-4 carcasses. Part of the China Lake NWC practice and testing area.
I believe Lil' John and the guys from Riverside and Corona fly up to Coyote Lake often... I drove there 15 years ago and did not see any runway markings of any sort. Maybe they know something about that lake being listed as an aux landing field.
Harper Dry Lake west of Barstow was the scene of a nightmare glider retrieve circa 1988, several of us had to go out and find an infamous local Hungarian/American glider icon who landed there with a student, we sank the van up to the axles in mud, spent a cold night digging, etc.
My point in all this was that in all my time stomping around those dry lakes, I never saw any runways, markings, or other evidence of their being "official" airports, save for a couple of exceptions: Rogers Dry Lake and Rosamond Dry Lake are marked as runways and are of course part of the Edwards AFB facility. Giant Rock Dry Lake was on the sectionals years ago, and even had a fly-in café built under a... giant rock. During the X-15 program, several remote Nevada and California dry lakes were scouted and approved as alternate landing areas, but I have no idea if they were actually marked up with black lines like Edwards is. And Groom Dry Lake, well I heard rumors there are a couple of pretty long lines marking a runway adjacent to a non-existent facility on the edge of the lakebed.
I have no doubt that some of the lakes were listed as aux landing fields on the old mail routes and airway system, but I've never heard or seen anything about them having been marked with runways, or windsocks, etc. There's a windsock on El Mirage lake, but it's next to the wreckage of a small cabin cruiser boat... maybe it was a seaplane base in the Pleistocene era
