# Relationship history for MSHA mine 1300032

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Fort Dodge Mine**

- 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:** Martin Marietta Materials Inc → Fort Dodge Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James W  Weaver et al → Fort Dodge Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Welp & Mc Carten Inc → Fort Dodge Mine; 1950-01-01 to 1980-03-05; source msha-controller-operator-history
- **controller_controls_mine:** Welp & Mc Carten Inc → Fort Dodge Mine; 1950-01-01 to 1980-03-05; source msha-controller-operator-history
- **controller_controls_operator:** Welp & Mc Carten Inc → Welp & Mc Carten Inc; 1950-01-01 to 1980-03-05; source msha-controller-operator-history
- **operator_operates_mine:** Welp & Mc Carten Inc → Fort Dodge Mine; 1980-03-06 to 1986-03-31; source msha-controller-operator-history
- **controller_controls_operator:** James W  Weaver et al → Welp & Mc Carten Inc; 1980-03-06 to 1986-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Fort Dodge Mine; 1986-04-01 to 2005-05-18; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1986-04-01 to 2005-05-18; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Fort Dodge Mine; 2005-05-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2005-05-19 to current/open; source msha-controller-operator-history