# Relationship history for MSHA mine 3608590

Current hierarchy: **Robert  Burns → Keystone Anthracite Corporation → Continental Strip**

- 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:** Michael R  Burns → Continental Strip; 1994-11-01 to 2011-02-28; source msha-controller-operator-history
- **controller_controls_mine:** City Trust Of Philadelphia → Continental Strip; 1996-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Girardville Coal Company → Continental Strip; 1996-10-01 to 2007-04-30; source msha-controller-operator-history
- **controller_controls_operator:** City Trust Of Philadelphia → Girardville Coal Company; 1996-10-01 to 2007-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Anthracite Corporation → Continental Strip; 2007-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael R  Burns → Keystone Anthracite Corporation; 2007-05-01 to 2011-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Burns → Continental Strip; 2011-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Burns → Keystone Anthracite Corporation; 2011-03-01 to current/open; source msha-controller-operator-history