# Relationship history for MSHA mine 1510677

Current hierarchy: **Helmandollar Sam → Dial Rock Coal Corp → No 1-A Mine (D)**

- 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:** Murray G Dale & Jan Gorgen → No 1-A Mine (D); 1977-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Little Hackney Creek Coal Company → No 1-A Mine (D); 1977-08-15 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Murray G Dale & Jan Gorgen → Little Hackney Creek Coal Company; 1977-08-15 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_mine:** United  Company → No 1-A Mine (D); 1980-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Little Hackney Creek Coal Company → No 1-A Mine (D); 1980-02-29 to 1980-04-20; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Little Hackney Creek Coal Company; 1980-02-29 to 1980-04-20; source msha-controller-operator-history
- **operator_operates_mine:** R A P Coal Company → No 1-A Mine (D); 1980-04-21 to 1981-04-29; source msha-controller-operator-history
- **controller_controls_mine:** Chaney Curtis E & A L--Robert Freeman → No 1-A Mine (D); 1980-04-21 to 1981-04-29; source msha-controller-operator-history
- **controller_controls_operator:** Chaney Curtis E & A L--Robert Freeman → R A P Coal Company; 1980-04-21 to 1981-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Dial Rock Coal Corp → No 1-A Mine (D); 1981-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Helmandollar Sam → No 1-A Mine (D); 1981-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helmandollar Sam → Dial Rock Coal Corp; 1981-04-30 to current/open; source msha-controller-operator-history