The note can be found at the Flatwoods lookout, on an endtable in the small cabin just below the base of the lookout tower.
I had to come try to find you, but I didn't dare bring Cheswick with me. I didn't want him to get hurt. I left him in the upstairs of the farmhouse we found just North of here. I thought you'd still be here, but I haven't been able to find you... If you get this, I'm gonna go back to the farmhouse. I hope Cheswick's still okay. Come find us when you get back...
If you make it back to the house and I'm not there, I hid the duffle under the porch by the front door. Please come back to us...
- Puppet Face