# Relationship history for MSHA mine 0400275

Current hierarchy: **Specialty Granules LLC → PVL Inc. → Panamint Valley Limestone Quarry**

- 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:** Kerr-Mc Gee Chemical Corp → Panamint Valley Limestone Quarry; 1950-01-01 to 1990-06-04; source msha-controller-operator-history
- **controller_controls_mine:** Kerr-McGee Corp → Panamint Valley Limestone Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kerr-McGee Corp → Kerr-Mc Gee Chemical Corp; 1950-01-01 to 1990-06-04; source msha-controller-operator-history
- **controller_controls_mine:** John  O'Brien et al → Panamint Valley Limestone Quarry; 1989-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Intermountain Mine Services Inc → Panamint Valley Limestone Quarry; 1990-06-05 to 1997-01-07; source msha-controller-operator-history
- **controller_controls_operator:** John  O'Brien et al → Intermountain Mine Services Inc; 1990-06-05 to 1997-01-07; source msha-controller-operator-history
- **controller_controls_operator:** David E  Drips et al → Intermountain Mine Services Inc; 1990-06-05 to 1997-01-07; source msha-controller-operator-history
- **operator_operates_mine:** Ace Cogeneration Company → Panamint Valley Limestone Quarry; 1997-01-08 to 2014-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Constellation Operating Services Inc  et al → Panamint Valley Limestone Quarry; 1997-01-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Constellation Operating Services Inc  et al → Ace Cogeneration Company; 1997-01-08 to 2014-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Arclight  et al → Ace Cogeneration Company; 1997-01-08 to 2014-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Shawn Barker Construction → Panamint Valley Limestone Quarry; 2014-12-01 to 2023-10-09; source msha-controller-operator-history
- **controller_controls_mine:** Shawn  Barker → Panamint Valley Limestone Quarry; 2014-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn  Barker → Shawn Barker Construction; 2014-12-01 to 2023-10-09; source msha-controller-operator-history
- **operator_operates_mine:** PVL Inc. → Panamint Valley Limestone Quarry; 2023-10-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Specialty Granules LLC → Panamint Valley Limestone Quarry; 2023-10-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Specialty Granules LLC → PVL Inc.; 2023-10-10 to current/open; source msha-controller-operator-history