Dearest Grace...

Dearest Grace... is a note found on a dead Wastelander in Fallout 3.

Location
From Old Olney travel west to the Red Rocket under the highway overpass; the one with the Jack-knifed Nuka-cola truck carrying the Quantum shipment. Take the road North past the three-way intersection. When you pass the billboard, begin looking East. The corpse is between standing and the knocked over trees.

Alternatively,

From Chaste Acres Dairy Farm, head northwest to the Red Rocket. Once there, take the road north and then turn and take the first turn east. Follow the road until you reach a building with a blue car. Go to the car, and from there, face west at a tree. Go to that tree, go past it and keep heading west to another tree. The Wastelander should be found dead under that tree and the other broken tree next to it.