# Relationship history for MSHA mine 2301076

Current hierarchy: **Mertens Construction Company Inc → Mertens Construction Company Inc → Todd Pit**

- 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:** Mertens Construction Company Inc → Todd Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W M Bledsoe & Sons Inc → Todd Pit; 1950-01-01 to 1978-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Bledsoe James A → Todd Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bledsoe James A → W M Bledsoe & Sons Inc; 1950-01-01 to 1978-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Mertens Construction Company Inc → Todd Pit; 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mertens Construction Company Inc → Mertens Construction Company Inc; 1978-09-01 to current/open; source msha-controller-operator-history