# Relationship history for MSHA mine 1515562

Current hierarchy: **Clark Leonard → Stephen Elkhorn Inc → 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

- **controller_controls_mine:** Boyd C Douglas & Randal Conn → No 1; 1985-04-01 to 1986-09-15; source msha-controller-operator-history
- **operator_operates_mine:** Fiesta Coal Company Inc → No 1; 1986-03-01 to 1986-09-09; source msha-controller-operator-history
- **controller_controls_operator:** Boyd C Douglas & Randal Conn → Fiesta Coal Company Inc; 1986-03-01 to 1986-09-09; source msha-controller-operator-history
- **operator_operates_mine:** Stephen Elkhorn Inc → No 1; 1986-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Clark Leonard → No 1; 1986-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Clark Leonard → Stephen Elkhorn Inc; 1986-09-10 to current/open; source msha-controller-operator-history