Exhibit 99.1 MARTIN MARIETTA REPORTS FIRST-QUARTER 2024 RESULTS First-Quarter Aggregates Gross Profit Per Ton Increased 14 Percent to $6.53 Magnesia Specialties Achieved Record Quarterly Gross Profit Quarter Highlights Include Significant Portfolio Enhancements Full-Year 2024 Guidance Raised to $2.37 Billion at the Midpoint RALEIGH, N.C. (April 30, 2024) – Martin Marietta Materials, Inc. (NYSE: MLM) (“Martin Marietta” or the “Company”), a leading national supplier of aggregates and heavy building materials, ...