# Relationship history for MSHA mine 3607813

Current hierarchy: **Lorenz Cynthia → Cal Mining → No 2 Vein Slope**

- 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

- **operator_operates_mine:** G B Mining Company → No 2 Vein Slope; 1986-07-01 to 1989-12-03; source msha-controller-operator-history
- **controller_controls_mine:** Vincent  Guarna et al → No 2 Vein Slope; 1986-07-01 to 1989-12-03; source msha-controller-operator-history
- **controller_controls_operator:** Vincent  Guarna et al → G B Mining Company; 1986-07-01 to 1989-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Hanna Coal Contractors → No 2 Vein Slope; 1989-12-04 to 1991-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Bixler Tom-Anthony Stanchick Et Al → No 2 Vein Slope; 1989-12-04 to 1991-09-09; source msha-controller-operator-history
- **controller_controls_operator:** Bixler Tom-Anthony Stanchick Et Al → Hanna Coal Contractors; 1989-12-04 to 1991-09-09; source msha-controller-operator-history
- **operator_operates_mine:** Cal Mining → No 2 Vein Slope; 1991-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Lorenz Cynthia → No 2 Vein Slope; 1991-09-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lorenz Cynthia → Cal Mining; 1991-09-10 to current/open; source msha-controller-operator-history