# Relationship history for MSHA mine 1504485

Current hierarchy: **Rogers Group Inc → Audubon Sand Company → Maceo Sand Dredge & Mill**

- 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:** Kapco Inc → Maceo Sand Dredge & Mill; 1950-01-01 to 1982-12-15; source msha-controller-operator-history
- **controller_controls_mine:** Thomas L  Kemp et al → Maceo Sand Dredge & Mill; 1950-01-01 to 1982-12-15; source msha-controller-operator-history
- **controller_controls_operator:** Thomas L  Kemp et al → Kapco Inc; 1950-01-01 to 1982-12-15; source msha-controller-operator-history
- **operator_operates_mine:** Audubon Sand Company → Maceo Sand Dredge & Mill; 1982-12-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rogers Group Inc → Maceo Sand Dredge & Mill; 1982-12-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rogers Group Inc → Audubon Sand Company; 1982-12-16 to current/open; source msha-controller-operator-history