# Relationship history for MSHA mine 3400120

Current hierarchy: **Berkshire Hathaway Inc → Acme Brick Company → MARKLAND 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

- **controller_controls_mine:** Justin Industries Inc → MARKLAND PIT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Oklahoma Brick & Block Corp → MARKLAND PIT; 1950-01-01 to 1986-04-16; source msha-controller-operator-history
- **controller_controls_mine:** Oklahoma Brick Corp → MARKLAND PIT; 1950-01-01 to 1986-04-16; source msha-controller-operator-history
- **controller_controls_operator:** Oklahoma Brick Corp → Oklahoma Brick & Block Corp; 1950-01-01 to 1986-04-16; source msha-controller-operator-history
- **controller_controls_mine:** Boral Limited → MARKLAND PIT; 1985-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Henderson Brick → MARKLAND PIT; 1986-04-17 to 1996-11-05; source msha-controller-operator-history
- **controller_controls_operator:** Boral Limited → Henderson Brick; 1986-04-17 to 1996-11-05; source msha-controller-operator-history
- **operator_operates_mine:** Acme Brick Company → MARKLAND PIT; 1996-11-06 to 2001-05-17; source msha-controller-operator-history
- **controller_controls_operator:** Justin Industries Inc → Acme Brick Company; 1996-11-06 to 2001-05-17; source msha-controller-operator-history
- **controller_controls_mine:** Berkshire Hathaway Inc → MARKLAND PIT; 2000-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Acme Brick Company → MARKLAND PIT; 2001-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Berkshire Hathaway Inc → Acme Brick Company; 2001-05-18 to current/open; source msha-controller-operator-history