Oxyrhopus vanidicus — Mimic False Coral Snake
This species was split from Oxyrhopus melanogenys by John D. Lynch in 2009, based on the shapes and pattern of the dark bands near the snake's neck. However, this seems like a pretty iffy distinction, so I won't argue with you if you consider this to be O. melanogenys.
I found this snake stretched out on the grass between the Santa Cruz facility's main building and bathroom building. I tried to get a photo of it there, but it decided to head back towards the forest rapidly, so I grabbed it and got a few posed photos the next day.