Exhibit 99.1 NEWS RELEASE Sylvamo First Quarter Results Meet Expectations, Strong Second Quarter Outlook Reflects Improving Conditions MEMPHIS, Tenn. – May 10, 2024 – Sylvamo (NYSE: SLVM), the world’s paper company, is releasing first quarter 2024 earnings. Financial Highlights - First Quarter vs. Fourth Quarter • Net income of $43 million ($1.02 per diluted share) vs. $49 million ($1.16 per diluted share) • Adjusted operating earnings1 of $45 million ($1.07 per diluted share) vs. $49 million ($1.16 per dil ...