# Relationship history for MSHA mine 1510696

Current hierarchy: **Williams Companies Inc → Johns Creek Elkhorn Coal Corp → Gannons Branch 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

- **controller_controls_mine:** General Energy Corp → Gannons Branch No 1 Mine; 1950-01-01 to 1982-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Shirl Ann Coal Company → Gannons Branch No 1 Mine; 1977-08-01 to 1978-08-14; source msha-controller-operator-history
- **controller_controls_mine:** Delford B  Endicott et al → Gannons Branch No 1 Mine; 1977-08-01 to 1978-08-14; source msha-controller-operator-history
- **controller_controls_operator:** Delford B  Endicott et al → Shirl Ann Coal Company; 1977-08-01 to 1978-08-14; source msha-controller-operator-history
- **operator_operates_mine:** Johns Creek Elkhorn Coal Corp → Gannons Branch No 1 Mine; 1978-08-15 to 1982-04-29; source msha-controller-operator-history
- **controller_controls_operator:** General Energy Corp → Johns Creek Elkhorn Coal Corp; 1978-08-15 to 1982-04-29; source msha-controller-operator-history
- **operator_operates_mine:** Johns Creek Elkhorn Coal Corp → Gannons Branch No 1 Mine; 1982-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Companies Inc → Gannons Branch No 1 Mine; 1982-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Williams Companies Inc → Johns Creek Elkhorn Coal Corp; 1982-04-30 to current/open; source msha-controller-operator-history