# Relationship history for MSHA mine 2200585

Current hierarchy: **Amy Sojourner  Eversole → Krystal Gravel → Krystal Gravel-Harmony**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Krystal Gravel → Krystal Gravel-Harmony; 1986-10-01 to 1990-04-01; source msha-controller-operator-history
- **controller_controls_mine:** John C  Sojourner → Krystal Gravel-Harmony; 1986-10-01 to 2013-12-31; source msha-controller-operator-history
- **controller_controls_operator:** John C  Sojourner → Krystal Gravel; 1986-10-01 to 1990-04-01; source msha-controller-operator-history
- **operator_operates_mine:** Southwest Paving Inc → Krystal Gravel-Harmony; 1990-04-02 to 1992-12-03; source msha-controller-operator-history
- **controller_controls_mine:** James H  Williams Sr → Krystal Gravel-Harmony; 1990-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James H  Williams Sr → Southwest Paving Inc; 1990-04-02 to 1992-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Krystal Gravel → Krystal Gravel-Harmony; 1992-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John C  Sojourner → Krystal Gravel; 1992-12-04 to 2013-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Amy Sojourner  Eversole → Krystal Gravel-Harmony; 2014-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amy Sojourner  Eversole → Krystal Gravel; 2014-01-01 to 1990-04-01; source msha-controller-operator-history
- **controller_controls_operator:** Amy Sojourner  Eversole → Krystal Gravel; 2014-01-01 to current/open; source msha-controller-operator-history