# Relationship history for MSHA mine 4100273

Current hierarchy: **John A  Oberman → D'Hanis Brick & Tile Company → Wolff 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** D'Hanis Brick & Tile Company → Wolff Pit; 1950-01-01 to 1988-05-10; source msha-controller-operator-history
- **controller_controls_mine:** John B  Nester  et al → Wolff Pit; 1950-01-01 to 1988-05-10; source msha-controller-operator-history
- **controller_controls_operator:** John B  Nester  et al → D'Hanis Brick & Tile Company; 1950-01-01 to 1988-05-10; source msha-controller-operator-history
- **operator_operates_mine:** D'Hanis Brick & Tile Company → Wolff Pit; 1988-05-11 to 1991-04-04; source msha-controller-operator-history
- **controller_controls_mine:** D'Hanis Manufacturing Co Et Al → Wolff Pit; 1988-05-11 to 1991-04-04; source msha-controller-operator-history
- **controller_controls_operator:** D'Hanis Manufacturing Co Et Al → D'Hanis Brick & Tile Company; 1988-05-11 to 1991-04-04; source msha-controller-operator-history
- **operator_operates_mine:** D'Hanis Brick & Tile Company → Wolff Pit; 1991-04-05 to 1995-07-25; source msha-controller-operator-history
- **controller_controls_mine:** William J  Crain → Wolff Pit; 1991-04-05 to 1995-07-25; source msha-controller-operator-history
- **controller_controls_operator:** William J  Crain → D'Hanis Brick & Tile Company; 1991-04-05 to 1995-07-25; source msha-controller-operator-history
- **operator_operates_mine:** D'Hanis Brick & Tile Company → Wolff Pit; 1995-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John A  Oberman → Wolff Pit; 1995-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John A  Oberman → D'Hanis Brick & Tile Company; 1995-07-26 to current/open; source msha-controller-operator-history