Nantahala Midland V 3.0

[Sumpter250]

The dead tree, and the grasses growing in the shallow pond, are almost exactly what one would expect.
The low ground stayed wet, and the tree flourished, until time changed things and the water got deeper. The regular visitation from cows could have had a major part in the change. Most trees need water, but don't survive their roots, and/or their trunks, being constantly wet.
I would think that after time, the mud would exist in "patches" around the pond. There would be places where the cows would choose not to "stand and drink". They might, for example, be uncomfortable with their backs to the rail line,... or any possible direction that predators might approach from. ( Yes, my mind does work that way )

I remember lots of these small round "ponds" out on the east end of Long Island. They were called "Scuttle Holes", and were merely depressions in the land that were lower than the water table height. They stayed full, year round.
In areas of Hills or mountains, they could simply be low areas that filled with rain run-off, no springs, or streams, connected with them.