Caching in with Three Dog

 refers to an unmarked quest in Fallout 3.

If you discover your father's whereabouts from someone other than Three Dog and still complete his Galaxy News Radio quest he compliments your dedication and then gives you the key and map location to his personal weapon stash at Hamilton's Hideaway.

The cache is behind a cell door in the northwestern-most area, behind some rubble.

Reward

 * Guns and Bullets
 * Mini Nuke
 * Stealth Boy
 * Combat Armor
 * Combat Helmet
 * Assault Rifle