I was there at the race, having just returned from Viet-Nam literally only a few weeks before, now serving with A Co. 75th Rangers who had just moved from Fort Benning to Fort Hood.
It was worse than what is shown in the Dave Friedman photos. On Saturday, there was several sessions, but I only watched one of them in full, that for the 5-litre cars, and parts of the session for the smaller cars (I thought there was only one such session, but it has been a while...). The rain was horrible. The track was flat as board and any concept of drainage was iffy. On Sunday, there was simply no way that they could use the track. And, yes, the water did rouse snakes out of their holes and onto the track in places. We saw several near one side of the pit area. It also sent other critters looking for high ground. In addition to the pond within the track area, there was a larger lake to the east of the track as well.
I did get to speak with Swede Savage, Dan Gurney, Sam Posey, Pete Revson, Mark Donohue, Parnelli Jones, and several others on Sunday morning as we all waited for the decision that was Obvious To Even The Untrained Eye to cancel/postpone the event. It was that bad. The only saving grace of the weekend was getting to spend time with those in the paddock.
The July F5000 event was during a typical boiling weekend in Texas. The USAC race got canceled on top of that. The place seemed to be cursed or Born Under a Bad Sign or something. Other than several drag racing meets and maybe a minor SCCA meeting or two, the Dallas track never did much. It was a vacant area for years and I think there is still a shopping center there now.