# Relationship history for MSHA mine 4606425

Current hierarchy: **Mounts Arden → Amber Coal Inc → Amber #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

- **operator_operates_mine:** Northern Amber Coal Company Inc → Amber #1; 1981-10-01 to 1983-08-29; source msha-controller-operator-history
- **controller_controls_mine:** Zeeman John → Amber #1; 1981-10-01 to 1983-08-29; source msha-controller-operator-history
- **controller_controls_operator:** Zeeman John → Northern Amber Coal Company Inc; 1981-10-01 to 1983-08-29; source msha-controller-operator-history
- **operator_operates_mine:** Amber Coal Inc → Amber #1; 1983-08-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mounts Arden → Amber #1; 1983-08-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mounts Arden → Amber Coal Inc; 1983-08-30 to current/open; source msha-controller-operator-history