# Relationship history for MSHA mine 1700574

Current hierarchy: **William  Sanborn → M.L. Lloyd & Sons → PORTABLE PLANT**

- 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:** Merle L. Lloyd & Sons → PORTABLE PLANT; 1985-05-01 to 2019-08-06; source msha-controller-operator-history
- **controller_controls_mine:** Jeffery  Lloyd → PORTABLE PLANT; 1985-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jeffery  Lloyd → Merle L. Lloyd & Sons; 1985-05-01 to 2019-08-06; source msha-controller-operator-history
- **operator_operates_mine:** M.L. Lloyd & Sons → PORTABLE PLANT; 2019-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William  Sanborn → PORTABLE PLANT; 2019-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Sanborn → M.L. Lloyd & Sons; 2019-08-07 to current/open; source msha-controller-operator-history