Longhorn Valley was a geographical location in the Highland Mountains of the UNSC-colonized planet Reach.
Before the Covenant invasion, the UNSC Army fireteam 3 Charlie was on patrol in the valley.
During the Battle of Reach, the valley was occupied by the Covenant, who built large defensive encampments in preparation for excavating the Forerunner complex beneath Menachite Mountain. It was scorched with atomic fire after a team of Spartan-IIs destroyed a nearby Covenant Cruiser with a Fury Tactical Nuclear Weapon, and is presumed to have ultimately been glassed.
It was a sloped region ten kilometers across, and contained a thick forest of Douglas firs, trampled fields, and the Big Horn River in the middle of it.
- ↑ Halo: Reach - Promotional Material: Patrol
- ↑ 2.0 2.1 Halo: First Strike, Page 27
- ↑ Halo: First Strike, Page 29-31