# Relationship history for MSHA mine 4607070

Current hierarchy: **Brooks Michael G → Desperado Coal Company Inc → Signal No 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:** Beacon Coal Company → Signal No 1; 1986-01-01 to 1988-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Lester Norman C → Signal No 1; 1986-01-01 to 1988-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Lester Norman C → Beacon Coal Company; 1986-01-01 to 1988-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Brooks Michael G → Signal No 1; 1988-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Desperado Coal Company Inc → Signal No 1; 1988-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brooks Michael G → Desperado Coal Company Inc; 1988-07-01 to current/open; source msha-controller-operator-history