# Relationship history for MSHA mine 0404276

Current hierarchy: **Robertson Corbin J Jr → Quintana Gypsum Company → Quintana Gypsum Company**

- 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:** Superior Gypsum Company → Quintana Gypsum Company; 1978-10-01 to 1983-07-10; source msha-controller-operator-history
- **controller_controls_mine:** Buttes Gas & Oil Company → Quintana Gypsum Company; 1978-10-01 to 1983-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Buttes Gas & Oil Company → Superior Gypsum Company; 1978-10-01 to 1983-07-10; source msha-controller-operator-history
- **operator_operates_mine:** Superior Gypsum Company → Quintana Gypsum Company; 1983-07-11 to 1986-03-12; source msha-controller-operator-history
- **controller_controls_mine:** Quintana Minerals Corp & J A Johnson → Quintana Gypsum Company; 1983-07-11 to 1986-03-12; source msha-controller-operator-history
- **controller_controls_operator:** Quintana Minerals Corp & J A Johnson → Superior Gypsum Company; 1983-07-11 to 1986-03-12; source msha-controller-operator-history
- **operator_operates_mine:** Quintana Gypsum Company → Quintana Gypsum Company; 1986-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robertson Corbin J Jr → Quintana Gypsum Company; 1986-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robertson Corbin J Jr → Quintana Gypsum Company; 1986-03-13 to current/open; source msha-controller-operator-history