Perhaps a Photinia???

Compare with Photinia serratifolia.

Photinia does fit. The NPS lists it as invasive within the park. How about this one:

https://www.marylandbiodiversity.com/viewSpecies.php?species=1550Oak. Quercus lyrata perhaps.

Likely Quercus nigra. Quercus lyrata is usually more strongly lobed, with 3-4 lobes per side.

Water oak

Water oak=Quercus nigra

Water oak and photinia are extremely common in arkansas. Photinia has been having widespread disease issues in the River Valley are for a few years now.

Thank you! Identifying trees is one of the joys of travel. I suspected it was an oak, but I would've guessed it to be in the white oak group since the lobes are more rounded.

I think the bristles are a diagnostic tool to separate it from the white oak group.

http://forestry.sfasu.edu/faculty/stovall/dendrology//images/tree_photos/quernigr/quernigr_leaf4.jpg