# Relationship history for MSHA mine 1509813

Current hierarchy: **Adams Benjamin C → G & G Coal Company → No 1 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:** Wright & Higgins Coal Company → No 1 Mine; 1976-07-13 to 1977-05-15; source msha-controller-operator-history
- **controller_controls_mine:** Wright Mitchell & James R Higgins → No 1 Mine; 1976-07-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wright Mitchell & James R Higgins → Wright & Higgins Coal Company; 1976-07-13 to 1977-05-15; source msha-controller-operator-history
- **operator_operates_mine:** G & G Coal Company → No 1 Mine; 1977-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Adams Benjamin C → No 1 Mine; 1977-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Adams Benjamin C → G & G Coal Company; 1977-05-16 to current/open; source msha-controller-operator-history