# Relationship history for MSHA mine 1508800

Current hierarchy: **Frost Andrew → Andy Frost Coal Company Inc → Prep Plant #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

- **operator_operates_mine:** Louisville Minerals Inc → Prep Plant #1; 1975-08-01 to 1977-06-30; source msha-controller-operator-history
- **controller_controls_mine:** White J L → Prep Plant #1; 1975-08-01 to 1977-06-30; source msha-controller-operator-history
- **controller_controls_operator:** White J L → Louisville Minerals Inc; 1975-08-01 to 1977-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Pat White Fuels Inc → Prep Plant #1; 1977-07-01 to 1986-08-25; source msha-controller-operator-history
- **controller_controls_mine:** White Pascual R → Prep Plant #1; 1977-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** White Pascual R → Pat White Fuels Inc; 1977-07-01 to 1986-08-25; source msha-controller-operator-history
- **controller_controls_mine:** Frost Andrew → Prep Plant #1; 1981-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Andy Frost Coal Company Inc → Prep Plant #1; 1986-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Frost Andrew → Andy Frost Coal Company Inc; 1986-08-26 to current/open; source msha-controller-operator-history