# Relationship history for MSHA mine 3607504

Current hierarchy: **Blaschak Holding Corp → Blaschak Coal Corp → Lost Creek #1 Strip Rngtwn Rntls Di**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** US Anthracite Corp → Lost Creek #1 Strip Rngtwn Rntls Di; 1976-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blaschak Holding Corp → Lost Creek #1 Strip Rngtwn Rntls Di; 1981-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-County Land & Coal Company → Lost Creek #1 Strip Rngtwn Rntls Di; 1983-10-01 to 1985-02-03; source msha-controller-operator-history
- **controller_controls_operator:** US Anthracite Corp → Tri-County Land & Coal Company; 1983-10-01 to 1985-02-03; source msha-controller-operator-history
- **operator_operates_mine:** Blaschak Coal Corp → Lost Creek #1 Strip Rngtwn Rntls Di; 1985-02-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blaschak Holding Corp → Blaschak Coal Corp; 1985-02-04 to current/open; source msha-controller-operator-history