# Relationship history for MSHA mine 1518894

Current hierarchy: **L Nicholas  Stevens → Keener Ridge Coals, Inc. → Mine 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:** L Nicholas  Stevens → Mine No. 1; 2004-06-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keener Ridge Coals, Inc. → Mine No. 1; 2005-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** L Nicholas  Stevens → Keener Ridge Coals, Inc.; 2005-06-27 to current/open; source msha-controller-operator-history