# Relationship history for MSHA mine 4500704

Current hierarchy: **Hobbick Herman C → Herman C Hobbick → Tennyson 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** J L Tennyson → Tennyson Pit; 1950-01-01 to 1980-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Tennyson J Lester → Tennyson Pit; 1950-01-01 to 1980-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Tennyson J Lester → J L Tennyson; 1950-01-01 to 1980-01-31; source msha-controller-operator-history
- **controller_controls_mine:** Gene  Simmons  et al → Tennyson Pit; 1950-01-01 to 1988-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Cascade Ready Mix → Tennyson Pit; 1980-02-01 to 1988-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Gene  Simmons  et al → Cascade Ready Mix; 1980-02-01 to 1988-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Walt  Miles et al → Tennyson Pit; 1983-04-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Concrete Nor'West → Tennyson Pit; 1988-12-01 to 1989-11-24; source msha-controller-operator-history
- **controller_controls_operator:** Walt  Miles et al → Concrete Nor'West; 1988-12-01 to 1989-11-24; source msha-controller-operator-history
- **operator_operates_mine:** Herman C Hobbick → Tennyson Pit; 1989-11-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hobbick Herman C → Tennyson Pit; 1989-11-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hobbick Herman C → Herman C Hobbick; 1989-11-25 to current/open; source msha-controller-operator-history