# Relationship history for MSHA mine 1515992

Current hierarchy: **Derek  Potter; David W  Potter → Potter Mining Company Inc → G-1 Refuse Site**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** James W  Potter et al → G-1 Refuse Site; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Potter Mining Company Inc → G-1 Refuse Site; 1987-04-01 to 1990-01-24; source msha-controller-operator-history
- **controller_controls_operator:** James W  Potter et al → Potter Mining Company Inc; 1987-04-01 to 1990-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Derek  Potter et al → G-1 Refuse Site; 1988-11-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Potter Mining Company Inc → G-1 Refuse Site; 1990-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Derek  Potter et al → Potter Mining Company Inc; 1990-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David W  Potter et al → Potter Mining Company Inc; 1990-01-25 to current/open; source msha-controller-operator-history