A mid game weapon, paired with the .44 revolver, with a longer range and higher damage. The revolver has a lower AP cost. An effective choice until one begins to find Gauss pistols, especially since AP .44 rounds are common, even in the end missions.
Sold by the Brotherhood after finishing Macomb and Peoria quests.
Four carried by Beastlords in Quincy (one carried by the Beastlord commandant in Hillary Eastwood's home. Also carried by the Beastlord in the northern sniper tower on top of Quincy's detention center).
The two stairwells in the main Mardin graveyard are both guarded by a single Beastlord each. Each holds another Desert Eagle.
On the Springfield mission, near the end is a building across the street from the church with two ghouls inside. The ghoul next to the red refrigerator has a crate behind him, in it is a Desert Eagle and some ammo.