# Relationship history for MSHA mine 4402672

Current hierarchy: **E Scott  Thompson → Thompson's Inc Of Danville VA → THOMPSON'S INC. #1 AND #2**

- 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:** Kendall Sand Works → THOMPSON'S INC. #1 AND #2; 1950-01-01 to 1979-01-04; source msha-controller-operator-history
- **controller_controls_mine:** Kendall Sand Works → THOMPSON'S INC. #1 AND #2; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kendall Sand Works → Kendall Sand Works; 1950-01-01 to 1979-01-04; source msha-controller-operator-history
- **operator_operates_mine:** Gravley Sand Works → THOMPSON'S INC. #1 AND #2; 1979-01-05 to 1998-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Dexter O  Gravley → THOMPSON'S INC. #1 AND #2; 1979-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dexter O  Gravley → Gravley Sand Works; 1979-01-05 to 1998-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Thompson'S Inc Of Danville Va → THOMPSON'S INC. #1 AND #2; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** E Scott  Thompson → THOMPSON'S INC. #1 AND #2; 1998-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** E Scott  Thompson → Thompson'S Inc Of Danville Va; 1998-06-01 to current/open; source msha-controller-operator-history