# Relationship history for MSHA mine 2301771

Current hierarchy: **Galveston Houston Company → De Soto Mining Company Inc → Richwoods 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:** Galveston Houston Company → Richwoods Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** De Soto Mining Company Inc → Richwoods Mine; 1979-12-01 to 1984-02-20; source msha-controller-operator-history
- **controller_controls_operator:** Galveston Houston Company → De Soto Mining Company Inc; 1979-12-01 to 1984-02-20; source msha-controller-operator-history
- **operator_operates_mine:** Agers Mining Inc → Richwoods Mine; 1984-02-21 to 1986-07-28; source msha-controller-operator-history
- **controller_controls_mine:** Agers David A → Richwoods Mine; 1984-02-21 to 1986-07-28; source msha-controller-operator-history
- **controller_controls_operator:** Agers David A → Agers Mining Inc; 1984-02-21 to 1986-07-28; source msha-controller-operator-history
- **operator_operates_mine:** De Soto Mining Company Inc → Richwoods Mine; 1986-07-29 to 1986-09-28; source msha-controller-operator-history
- **controller_controls_operator:** Galveston Houston Company → De Soto Mining Company Inc; 1986-07-29 to 1986-09-28; source msha-controller-operator-history
- **operator_operates_mine:** Williams Mining Company Inc → Richwoods Mine; 1986-09-29 to 1988-06-28; source msha-controller-operator-history
- **controller_controls_mine:** Williams Arthur E → Richwoods Mine; 1986-09-29 to 1988-06-28; source msha-controller-operator-history
- **controller_controls_operator:** Williams Arthur E → Williams Mining Company Inc; 1986-09-29 to 1988-06-28; source msha-controller-operator-history
- **operator_operates_mine:** De Soto Mining Company Inc → Richwoods Mine; 1988-06-29 to 1988-11-20; source msha-controller-operator-history
- **controller_controls_operator:** Galveston Houston Company → De Soto Mining Company Inc; 1988-06-29 to 1988-11-20; source msha-controller-operator-history
- **operator_operates_mine:** Richwoods Mining Company → Richwoods Mine; 1988-11-21 to 1989-05-01; source msha-controller-operator-history
- **controller_controls_mine:** Johnson Sandra G → Richwoods Mine; 1988-11-21 to 1989-05-01; source msha-controller-operator-history
- **controller_controls_operator:** Johnson Sandra G → Richwoods Mining Company; 1988-11-21 to 1989-05-01; source msha-controller-operator-history
- **operator_operates_mine:** De Soto Mining Company Inc → Richwoods Mine; 1989-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Galveston Houston Company → De Soto Mining Company Inc; 1989-05-02 to current/open; source msha-controller-operator-history