# Relationship history for MSHA mine 0801123

Current hierarchy: **Dennis L  Smith → Dennis L Smith Inc → 20 Mile Bend Pit**

- 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:** Dennis L  Smith → 20 Mile Bend Pit; 1988-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dennis L Smith Inc → 20 Mile Bend Pit; 1989-02-01 to 1990-11-14; source msha-controller-operator-history
- **controller_controls_operator:** Dennis L  Smith → Dennis L Smith Inc; 1989-02-01 to 1990-11-14; source msha-controller-operator-history
- **controller_controls_mine:** Robert D  Martin et al → 20 Mile Bend Pit; 1990-10-30 to 1991-08-06; source msha-controller-operator-history
- **operator_operates_mine:** Martin Paving Company → 20 Mile Bend Pit; 1990-11-15 to 1991-08-06; source msha-controller-operator-history
- **controller_controls_operator:** Robert D  Martin et al → Martin Paving Company; 1990-11-15 to 1991-08-06; source msha-controller-operator-history
- **operator_operates_mine:** Dennis L Smith Inc → 20 Mile Bend Pit; 1991-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dennis L  Smith → Dennis L Smith Inc; 1991-08-07 to current/open; source msha-controller-operator-history