# Relationship history for MSHA mine 1101132

Current hierarchy: **Albert  Lamb → Pontiac Stone Company → Weston Stone Div Plant #2**

- 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

- **controller_controls_mine:** Albert  Lamb → Weston Stone Div Plant #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Howard Arnold Construction Company Inc → Weston Stone Div Plant #2; 1950-01-01 to 1978-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Arnold Harold Construction Company Inc → Weston Stone Div Plant #2; 1950-01-01 to 1978-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Arnold Harold Construction Company Inc → Howard Arnold Construction Company Inc; 1950-01-01 to 1978-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Pontiac Stone Company → Weston Stone Div Plant #2; 1978-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Albert  Lamb → Pontiac Stone Company; 1978-04-01 to current/open; source msha-controller-operator-history