Ranger substation Eagle joins two other substations in Zion, including Ranger substation Peregrine and Osprey. All three have similar layouts. Substation Eagle has a single room on the lower floor that contains various crafting items/common loot and a staircase that leads to a single room living quarters for the ranger.
The living quarters area includes a bookshelf, bed, table, and a first aid box. At the top is a locked gun case with a leveled lock. The entire building is marked with the chalk-white handprints of the Dead Horses scouts.
When Follows-Chalk is traveling with the Courier, reaching this location will reveal nearby map markers and inspire a heightened sense of awareness (Perception +3) for three minutes with the Well-Stacked Cairns perk. The map markers revealed here include Bighorn Bluff, the Bend bridge, and Court Fork Overlook.