# Relationship history for MSHA mine 1509366

Current hierarchy: **Kramer Gerald → Underground Recovery Inc → Stephens Mine**

- 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:** Petty J W → Stephens Mine; 1975-02-19 to 1977-08-29; source msha-controller-operator-history
- **operator_operates_mine:** Underground Recovery Inc → Stephens Mine; 1975-11-24 to 1977-08-29; source msha-controller-operator-history
- **controller_controls_operator:** Petty J W → Underground Recovery Inc; 1975-11-24 to 1977-08-29; source msha-controller-operator-history
- **operator_operates_mine:** Underground Recovery Inc → Stephens Mine; 1977-08-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kramer Gerald → Stephens Mine; 1977-08-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kramer Gerald → Underground Recovery Inc; 1977-08-30 to current/open; source msha-controller-operator-history