# Relationship history for MSHA mine 2401525

Current hierarchy: **Fulgham Don-Tom → Fulgham'S Dert Gulch Mine → Dert Gulch Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Fulgham'S Dert Gulch Mine → Dert Gulch Mine; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fulgham Don-Tom Et Al → Dert Gulch Mine; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fulgham Don-Tom Et Al → Fulgham'S Dert Gulch Mine; 1980-04-01 to current/open; source msha-controller-operator-history