Looks like a classic situation developing in the Congaree Swamp: lost man, with 2 small children.

Tough terrain there, but at least the weather has been mild.

The article you linked says they have the NPS from Great Smokey NP helping:
This is good, since when searches get this big they can very quickly turn into a total clusterflock if not properly managed. The NPS along with NASAR has been in the forefront of developing methods for conducting and managing large ground searches.

Best hopes for a successful and happy ending to this search!

As a bit of follow up, and comparison with the incident hikermor posted in another thread, most "SAR" incidents are resolved fairly quickly. Nationwide, something greater than 90% of SAR incidents are handled in the first "operational period", in other words within the first day. Often these are more rescues rather than searches.

For example, a hiker is reported missing. A couple of hasty teams are sent up the most likely route. The hiker is found with an injured ankle and is brought down. Or, as in the example hikermor posted on another thread, someone reports an injured or trapped person. A medical and/or rescue team is dispatched to a known location, and deals with the incident. These kinds of things happen all the time. Often, they don't make the mainstream news at all, unless there is a fatality.

In a much smaller number of cases, the incident extends over several days, and may involve dozens, perhaps even hundreds of people, from multiple agencies and organizations. Typically (though not always), these are searches for missing people. When incidents grow this large and extend over many days, management of the operation becomes very complex. A poorly managed incident can lead a bad outcome for the missing person, and can unnecessarily endanger rescuers.

Years ago, after a number of very large, very badly run searches, with very bad outcomes, NASAR developed their MLPI course. This course teaches people how to organize and run large scale land search operations. More recently, other specialized courses for using the Incident Management System in large ground searches have been developed. The NPS has been one of the agencies heavily involved in developing these programs and getting their people trained up.

"Typically (though not always), these are searches for missing people. When incidents grow this large and extend over many days, management of the operation becomes very complex."

To put it mildly! Complexity, which usually involves media interest, is increased if the search subject is other than the usual young adult male, and the operations area is accessible to media crews. After about day four or five, alternative hypotheses rear their heads and you enter the "abducted by aliens" phase. In another day or two, you will begin to hear from psychics with their vision of events and circumstances. Sometimes these may be obvious scams, but often they are completely sincere. I was assigned to follow up with one such psychic on a prolonged, media heavy search. We traveled to the spot where we would located the subject in the psychics car, on the psychics gas, finding nothing (the area had been covered days before). We never reached a successful conclusion on this operation, and it still comes up occasionally.

Fortunately, most operations last less than 24 hours.....

+1

Quote from article: "Ballard said she received a text from Kimbler saying the three were lost.[snip] A cell phone is still inside the cab along with his cab logbook"

How was the text message sent?

Second cell phone? Did the kids have a Cell phone?

I'm getting way too suspicious in my old age. . .

Best to not jump to hasty conclusions based on what you read in the mainstream media. In SAR cases, the media gets things wrong at least as often as they get things right. (And that is being rather optimistic!)

One of the hallmarks of a well run search is that investigation by law enforcement begins immediatly and runs simultaneously with the field search. It is a very good bet that by now the authorities have determined if the text message came from the cell phone found in the cab, or from another phone (and if so which other phone). They will also be using whatever info can be extracted from the text ping to narrow down (or expand) the initial search area. The have also likely started to discreetly do background checks (criminal, financial, etc) on both the father and mother.

If this search is being run properly, and they are still treating it as a wilderness search (rather than a law enforcement problem), then we can assume they have at least some reason to do so. That's not to say that "something fishy" may not have occured, but it is way too early to jump to conclusions based on what little info has filtered through the press. The latest report I could find with google says they plan to continue ground searches tomorrow.

kids probably have a better phone than Dad.

If all you know about a SAR operation comes from the media, you are definitely under informed. The more complex the operation, the less you know.

To ramble on a bit more about searches, "fishy" and otherwise, consider the dilemma faced by the searchers in this case.

Suppose you suspect it is a planned disapearence, and the father and kids are not really lost in the woods? Do you then suspend the ground search early? If you are wrong, then two children and their father might die as a result. Not something I would want on my conscience.

On the the other hand, suppose you continue to assume they are just lost in the woods, and don't consider othe possibilities, such as foul play? Then the children might be in very grave danger of another sort, and the perpetrator has an ever growing head start to escape.

That is why, as I suggested up thread, a good search will pursue both possibilities simultaneously. You try to conduct the most thorough, systematic ground search you can do. At the same time, law enforcement is doing as thorough and systematic of an investigation as possible. And the search managers must always try to maintain an open mind to all possibilities. That seems to be what is happening in this case: Search on for father, 2 kids in SC national park

Things just got more complicated. Significant rain is coming through the area tonight through Wednesday. The Congaree is a big swamp that will flood in a heartbeat.

According to the NPS "J.R. Kimbler, his 6-year-old daughter, Jade, and 10-year-old son, Dakota, were not prepared to overnight in the woods, and they have no food water or rain gear."