# Relationship history for MSHA mine 1515149

Current hierarchy: **Sloan Curtis & David Belcher → Enduro Coal Company Inc → 3-L**

- 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:** Sloan Curtis & David Belcher → 3-L; 1975-04-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Fiesta Coal Company Inc → 3-L; 1985-04-01 to 1986-03-23; source msha-controller-operator-history
- **controller_controls_mine:** Boyd C Douglas & Randal Conn → 3-L; 1985-04-01 to 1986-09-15; source msha-controller-operator-history
- **controller_controls_operator:** Boyd C Douglas & Randal Conn → Fiesta Coal Company Inc; 1985-04-01 to 1986-03-23; source msha-controller-operator-history
- **operator_operates_mine:** Enduro Coal Company Inc → 3-L; 1986-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sloan Curtis & David Belcher → Enduro Coal Company Inc; 1986-03-24 to current/open; source msha-controller-operator-history