Ooo, yeah, not a great design for where it is.
Something like this?
A wider shot of whole pen, showing any slope that contributes to water gathering and/or might help it move away, might garner other ideas.
Why is that one part muddier than the rest?
Is there copious runoff standing in puddles there...or....???
These loads are large...you really want someplace a pile can sit for months as you transfer a bit at a time to the run.
This 2 loads: