# Relationship history for MSHA mine 1200760

Current hierarchy: **Blake M  Blann; Michael  Blann; Martha  Blann → BLANN & SON L.L.C. II → BLANN & SON SAND & GRAVEL**

- 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

- **operator_operates_mine:** Sullivan County Highway Department → BLANN & SON SAND & GRAVEL; 1950-01-01 to 2016-02-29; source msha-controller-operator-history
- **controller_controls_mine:** Sullivan County Highway Department → BLANN & SON SAND & GRAVEL; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sullivan County Highway Department → Sullivan County Highway Department; 1950-01-01 to 2016-02-29; source msha-controller-operator-history
- **operator_operates_mine:** BLANN & SON L.L.C. II → BLANN & SON SAND & GRAVEL; 2016-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blake M  Blann et al → BLANN & SON SAND & GRAVEL; 2016-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blake M  Blann et al → BLANN & SON L.L.C. II; 2016-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martha  Blann et al → BLANN & SON L.L.C. II; 2016-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Blann et al → BLANN & SON L.L.C. II; 2016-03-01 to current/open; source msha-controller-operator-history