# Relationship history for MSHA mine 0301578

Current hierarchy: **William  Boorhem → Boorhem-Fields Inc → South Hampton 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

- **controller_controls_mine:** Ben M Hogan Company Inc → South Hampton Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William  Boorhem  et al → South Hampton Plant; 1979-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** L A Gravel Inc → South Hampton Plant; 1984-04-01 to 1987-04-14; source msha-controller-operator-history
- **controller_controls_mine:** Hill D B Iii → South Hampton Plant; 1984-04-01 to 1987-04-14; source msha-controller-operator-history
- **controller_controls_operator:** Hill D B Iii → L A Gravel Inc; 1984-04-01 to 1987-04-14; source msha-controller-operator-history
- **operator_operates_mine:** St Francis Material Company → South Hampton Plant; 1987-04-15 to 1987-07-17; source msha-controller-operator-history
- **controller_controls_operator:** Ben M Hogan Company Inc → St Francis Material Company; 1987-04-15 to 1987-07-17; source msha-controller-operator-history
- **operator_operates_mine:** Boorhem-Fields Inc → South Hampton Plant; 1987-07-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Boorhem  et al → Boorhem-Fields Inc; 1987-07-18 to current/open; source msha-controller-operator-history