# Relationship history for MSHA mine 1001749

Current hierarchy: **Lloyd G  Merrill → J K Merrill & Sons Incorporated → George's  Portable Plant**

- 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:** George T  Merrill  et al → George's  Portable Plant; 1979-04-01 to 2015-12-31; source msha-controller-operator-history
- **operator_operates_mine:** J K Merrill & Sons Incorporated → George's  Portable Plant; 1986-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George T  Merrill  et al → J K Merrill & Sons Incorporated; 1986-07-01 to 2015-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Lloyd G  Merrill → George's  Portable Plant; 2016-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lloyd G  Merrill → J K Merrill & Sons Incorporated; 2016-01-01 to current/open; source msha-controller-operator-history