# Relationship history for MSHA mine 2700334

Current hierarchy: **Robert P  Ambrose; Robert J  Ambrose → Ambrose Bros Inc → Portable Plant #1**

- 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:** Edward A  Ambrose et al → Portable Plant #1; 1950-01-01 to 2015-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Ambrose Bros Inc → Portable Plant #1; 1995-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward A  Ambrose et al → Ambrose Bros Inc; 1995-11-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Robert P  Ambrose et al → Ambrose Bros Inc; 1995-11-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Robert J  Ambrose et al → Portable Plant #1; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert J  Ambrose et al → Ambrose Bros Inc; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert P  Ambrose et al → Ambrose Bros Inc; 2016-01-01 to current/open; source msha-controller-operator-history