# Relationship history for MSHA mine 1301835

Current hierarchy: **Edward D  Tschiggfrie → Tschiggfrie Stone Company → Hermsen 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:** Beecher Robert → Hermsen Quarry; 1950-01-01 to 1983-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Beecher Quarries Ltd → Hermsen Quarry; 1978-03-09 to 1982-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Beecher Robert → Beecher Quarries Ltd; 1978-03-09 to 1982-11-08; source msha-controller-operator-history
- **controller_controls_mine:** Edward D  Tschiggfrie → Hermsen Quarry; 1982-11-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tschiggfrie Stone Company → Hermsen Quarry; 1982-11-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward D  Tschiggfrie → Tschiggfrie Stone Company; 1982-11-09 to current/open; source msha-controller-operator-history