# Relationship history for MSHA mine 4000095

Current hierarchy: **Howard L  Mercer → Turner Brothers Stone of Crossville, Inc → Turner Brothers Stone 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:** Turner Brothers Stone Company Inc → Turner Brothers Stone Quarry; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_mine:** Walter A  Turner → Turner Brothers Stone Quarry; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **controller_controls_operator:** Walter A  Turner → Turner Brothers Stone Company Inc; 1950-01-01 to 1981-03-25; source msha-controller-operator-history
- **operator_operates_mine:** Turner Brothers Stone Of Crossville, Inc → Turner Brothers Stone Quarry; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Howard L  Mercer → Turner Brothers Stone Quarry; 1981-03-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Howard L  Mercer → Turner Brothers Stone Of Crossville, Inc; 1981-03-26 to current/open; source msha-controller-operator-history