# Relationship history for MSHA mine 4101045

Current hierarchy: **Tyler Pipe Industries Inc → Tyler Sand Company → Tyler Sand 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:** Big Sandy Sand Company Inc → Tyler Sand Company; 1950-01-01 to 1981-06-16; source msha-controller-operator-history
- **controller_controls_mine:** Dennis F  Wright → Tyler Sand Company; 1950-01-01 to 2018-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Dennis F  Wright → Big Sandy Sand Company Inc; 1950-01-01 to 1981-06-16; source msha-controller-operator-history
- **operator_operates_mine:** Tyler Sand Company → Tyler Sand Company; 1981-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tyler Pipe Industries Inc → Tyler Sand Company; 1981-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tyler Pipe Industries Inc → Tyler Sand Company; 1981-06-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Laurel A  Wright → Tyler Sand Company; 2018-05-01 to 2019-10-13; source msha-controller-operator-history
- **controller_controls_operator:** Laurel A  Wright → Big Sandy Sand Company Inc; 2018-05-01 to 1981-06-16; source msha-controller-operator-history
- **controller_controls_mine:** LeeAnn  Bailey et al → Tyler Sand Company; 2019-10-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** LeeAnn  Bailey et al → Big Sandy Sand Company Inc; 2019-10-14 to 1981-06-16; source msha-controller-operator-history
- **controller_controls_operator:** John T  Wright et al → Big Sandy Sand Company Inc; 2019-10-14 to 1981-06-16; source msha-controller-operator-history