# Relationship history for MSHA mine 2700315

Current hierarchy: **Robert P  Ambrose; Robert J  Ambrose → Ambrose Brothers Inc → PORTABLE CRUSHING PLANT 128X108**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Robert P  Ambrose et al → PORTABLE CRUSHING PLANT 128X108; 1950-01-01 to 2015-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Ambrose Brothers Inc → PORTABLE CRUSHING PLANT 128X108; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert P  Ambrose et al → Ambrose Brothers Inc; 1997-10-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Edward A  Ambrose et al → Ambrose Brothers Inc; 1997-10-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Robert P  Ambrose et al → PORTABLE CRUSHING PLANT 128X108; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert P  Ambrose et al → Ambrose Brothers Inc; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert J  Ambrose et al → Ambrose Brothers Inc; 2016-01-01 to current/open; source msha-controller-operator-history