# Relationship history for MSHA mine 2900018

Current hierarchy: **Daniel L  Maxwell → Southwest Exploration Inc → K B Mine**

- 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:** Mathis & Mathis Mining Company → K B Mine; 1950-01-01 to 1993-02-28; source msha-controller-operator-history
- **controller_controls_mine:** R W  Mathias et al → K B Mine; 1950-01-01 to 1993-03-31; source msha-controller-operator-history
- **controller_controls_operator:** R W  Mathias et al → Mathis & Mathis Mining Company; 1950-01-01 to 1993-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Daniel L  Maxwell → K B Mine; 1990-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southwest Silica Flux Company Inc → K B Mine; 1993-03-01 to 2002-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Daniel L  Maxwell → K B Mine; 1993-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel L  Maxwell → Southwest Silica Flux Company Inc; 1993-03-01 to 2002-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Southwest Exploration Inc → K B Mine; 2002-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Daniel L  Maxwell → Southwest Exploration Inc; 2002-10-01 to current/open; source msha-controller-operator-history