# Relationship history for MSHA mine 3502834

Current hierarchy: **Houck C T & Chuck Mc Call → Houck & Mc Call Corp → Carver Pit & Plant #3**

- 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

- **operator_operates_mine:** Houck & Mc Call Corp → Carver Pit & Plant #3; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Houck C T & Chuck Mc Call → Carver Pit & Plant #3; 1978-03-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Houck C T & Chuck Mc Call → Houck & Mc Call Corp; 1978-03-09 to current/open; source msha-controller-operator-history