# Relationship history for MSHA mine 4102341

Current hierarchy: **Lawrence Richard Robert Jr → Baytown Sand & Clay → Baytown Sand Pit**

- 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:** Baytown Sand & Clay → Baytown Sand Pit; 1950-01-01 to 1980-06-25; source msha-controller-operator-history
- **controller_controls_mine:** Guidry Patrick → Baytown Sand Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Guidry Patrick → Baytown Sand & Clay; 1950-01-01 to 1980-06-25; source msha-controller-operator-history
- **operator_operates_mine:** Baytown Sand & Clay → Baytown Sand Pit; 1980-06-26 to 1981-07-18; source msha-controller-operator-history
- **controller_controls_mine:** A Donovan  Smart et al → Baytown Sand Pit; 1980-06-26 to 1981-07-18; source msha-controller-operator-history
- **controller_controls_operator:** A Donovan  Smart et al → Baytown Sand & Clay; 1980-06-26 to 1981-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Baytown Sand & Clay → Baytown Sand Pit; 1981-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lawrence Richard Robert Jr → Baytown Sand Pit; 1981-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lawrence Richard Robert Jr → Baytown Sand & Clay; 1981-07-19 to current/open; source msha-controller-operator-history