# Relationship history for MSHA mine 1001988

Current hierarchy: **Ernie Ray  Hale → Sierra Stone Inc → Warm Springs**

- 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:** Diamondfield Quartzite → Warm Springs; 2000-11-01 to 2002-07-16; source msha-controller-operator-history
- **controller_controls_mine:** Ernie Ray  Hale → Warm Springs; 2000-11-01 to 2002-07-16; source msha-controller-operator-history
- **controller_controls_operator:** Ernie Ray  Hale → Diamondfield Quartzite; 2000-11-01 to 2002-07-16; source msha-controller-operator-history
- **controller_controls_mine:** Ernie Ray  Hale → Warm Springs; 2001-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sierra Stone Inc → Warm Springs; 2002-07-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ernie Ray  Hale → Sierra Stone Inc; 2002-07-17 to current/open; source msha-controller-operator-history