# Relationship history for MSHA mine 2200685

Current hierarchy: **Paige W  Farrish; David N  Farrish → Nelson Materials Inc → TRIBBLE PIT**

- 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

- **controller_controls_mine:** David N  Farrish et al → TRIBBLE PIT; 1982-11-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Nelson Materials Inc → TRIBBLE PIT; 1997-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David N  Farrish et al → Nelson Materials Inc; 1997-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paige W  Farrish et al → Nelson Materials Inc; 1997-06-01 to current/open; source msha-controller-operator-history