# Relationship history for MSHA mine 2902093

Current hierarchy: **Guerrero  Martinez → Martinez Sand & Gravel → MARTINEZ 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:** Heddleston Mining → MARTINEZ PIT; 1992-05-01 to 1994-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Jim  Heddleston → MARTINEZ PIT; 1992-05-01 to 1994-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Jim  Heddleston → Heddleston Mining; 1992-05-01 to 1994-03-09; source msha-controller-operator-history
- **operator_operates_mine:** Anthony Builders → MARTINEZ PIT; 1994-03-10 to 1995-04-09; source msha-controller-operator-history
- **controller_controls_mine:** Arturo  Longoria → MARTINEZ PIT; 1994-03-10 to 1995-04-09; source msha-controller-operator-history
- **controller_controls_operator:** Arturo  Longoria → Anthony Builders; 1994-03-10 to 1995-04-09; source msha-controller-operator-history
- **operator_operates_mine:** Martinez Sand & Gravel → MARTINEZ PIT; 1995-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Guerrero  Martinez → MARTINEZ PIT; 1995-04-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Guerrero  Martinez → Martinez Sand & Gravel; 1995-04-10 to current/open; source msha-controller-operator-history