It really isn't a park, they just put some features down the right hand side of of Sapphire. On Sunday it was a 12' slight down with donkey, a 12' flat, a 24' down flat box (three 8' boxes together), a tiny 6' cannon, a 12' flat, a 25' flat up, and an olley on 15' tube. The main problem is regular skier traffic, you are sharing the trail with a bunch of people who do not know to stay away the features if they are not using them.
The mountain made this awful edit, which gives you a look at some of the features.
CHILL Early season Park EDIT on Sapphire at Okemo Mountain Resort from Okemo Mountain Resort on Vimeo.