# Relationship history for MSHA mine 2901984

Current hierarchy: **Olan  Booher → Booher Sand & Gravel → DEXTER 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:** Monterey Construction Company → DEXTER PIT; 1985-03-01 to 1989-05-07; source msha-controller-operator-history
- **controller_controls_mine:** Atkinson Guy F Company → DEXTER PIT; 1985-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atkinson Guy F Company → Monterey Construction Company; 1985-03-01 to 1989-05-07; source msha-controller-operator-history
- **operator_operates_mine:** Booher Sand & Gravel → DEXTER PIT; 1989-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Olan  Booher → DEXTER PIT; 1989-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Olan  Booher → Booher Sand & Gravel; 1989-05-08 to current/open; source msha-controller-operator-history