The 51,500-acre area was declared a national historic landmark in 1975. The landmark includes Base Camp, where the scientists and support group lived; Ground Zero, where the bomb was placed for the explosion; and the Schmidt/McDonald Ranch House, where the plutonium core to the bomb was assembled. Visitors to a Trinity Site Open House are given the opportunity to visit Jumbo, Ground Zero, and the Ranch House. In addition, one of the old instrumentation bunkers is visible beside the road just west of Ground Zero.
NOTICE: The Trinity Site Open House scheduled for Saturday, 18 October 2025, has been cancelled. Please refer all questions regarding the Open House to the White Sands Missile Range Public Affairs Office at 575-678-1134 or usarmy.wsmr.atec.list.pao@army.mil
| Trinity Site Open House Dates | 2025 | 2026 | 2027 | 2028 |
| Third Saturday in October | Cancelled | 17 October | 16 October | 21 October |
This marker shows the location of Stallion Range Gate, the general public entrance to Trinity Site off of Highway 380.