# Relationship history for MSHA mine 3606984

Current hierarchy: **Leasure Donald V Jr & Douglas → Doug Coal Company → Doug Coal Co**

- 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:** Doug Coal Company → Doug Coal Co; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Leasure Donald V Jr & Douglas → Doug Coal Co; 1980-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leasure Donald V Jr & Douglas → Doug Coal Company; 1980-06-01 to current/open; source msha-controller-operator-history