If you look on the left side, there is something that looks like a fossilized piece of wood on the ground. It probably is a rock that by chance looks
like a log, but it's nice to imagine.
That picture is a few years old and has had many threads about it here on ATS in the past.
It's most likely a rock. There are other pictures taken of that area with many other objects in that same are with that exact same texture, but
since they are not long and thin, they don't look like wood -- they look like rocks.