Under the treaty, the Desert Rangers were absorbed into the New California Republic Rangers. In return, the New California Republic took on the burden of protecting Hoover Dam, New Vegas, and southern portions of Nevada against the forces of the Caesar's Legion.
The Desert Rangers brought their traditional garb, military combat armor worn underneath desert dusters, along with them (note that the NCR Veteran Rangers had their infamous suits of Black Armor long before the Desert Rangers were merged with the NCR Rangers). The combination proved to be popular and by 2281, veteran Rangers of the Republic all wear a similar combination of clothing to distinguish themselves from the NCR Army and other Rangers.
The Ranger Unification Treaty is mentioned only in Fallout: New Vegas.
- Mojave outpost monument placard:
"In the year 2271, the Desert Rangers of Nevada and rangers of the New California Republic met at this spot to sign the Ranger Unification Treaty. Under this treaty, the Desert Rangers agreed to be absorbed into the NCR in exchange for NCR's protection of Hoover Dam, New Vegas, and southern Nevada against the forces of Caesar's Legion."
- The Courier: "Why are the rangers here?"
Hanlon: "There's a lot of answers to that question, but it started with the Ranger Unification Treaty. We weren't always the only show in town. Nevada had its own posse, the Desert Rangers. They fought Caesar even farther east, out in Arizona. Didn't go well for them. Years back, we met with the Desert Rangers at Mojave Outpost and agreed to help them against Caesar if they would join the NCR."
- The Black Armor bears the markings of the former Los Angeles Police Department and was salvaged from the ruins of what was once the city of Los Angeles. This armor was clearly in the Republic's possession long before the Ranger Unification Treaty.
- NCR Ranger Veteran
- Mojave Outpost