# Relationship history for MSHA mine 2200788

Current hierarchy: **Amy Sojourner  Eversole → Krystal Gravel Inc → Krystal Gravel-Coor 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** John C  Sojourner → Krystal Gravel-Coor Springs; 1986-10-01 to 2013-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Krystal Gravel Inc → Krystal Gravel-Coor Springs; 2008-11-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John C  Sojourner → Krystal Gravel Inc; 2008-11-19 to 2013-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Amy Sojourner  Eversole → Krystal Gravel-Coor Springs; 2014-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amy Sojourner  Eversole → Krystal Gravel Inc; 2014-01-01 to current/open; source msha-controller-operator-history