# Relationship history for MSHA mine 4103740

Current hierarchy: **Tom  Alkusari → Alkusari Texas Limestone Corp → Alkusari Quarry**

- 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:** Lynn L  Northrup Jr → Alkusari Quarry; 1991-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** American Limestone Company → Alkusari Quarry; 1992-09-01 to 1993-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Lynn L  Northrup Jr → American Limestone Company; 1992-09-01 to 1993-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Lueders Limestone → Alkusari Quarry; 1993-10-01 to 1997-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Weldon  Tredemeyer → Alkusari Quarry; 1993-10-01 to 1997-09-14; source msha-controller-operator-history
- **controller_controls_operator:** Weldon  Tredemeyer → Lueders Limestone; 1993-10-01 to 1997-09-14; source msha-controller-operator-history
- **operator_operates_mine:** Alkusari Texas Limestone Corp → Alkusari Quarry; 1997-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tom  Alkusari → Alkusari Quarry; 1997-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Alkusari → Alkusari Texas Limestone Corp; 1997-09-15 to current/open; source msha-controller-operator-history