By 2030, early-onset colorectal cancer (EOCRC) is expected to become the leading cancer-related cause of death for people age 20 to 49. To improve understanding of this phenomenon, we analyzed the geographic determinants of EOCRC in Utah by examining county-level incidence and mortality. We linked data from the Utah Population Database to the Utah Cancer Registry to identify residents (age 18â49) diagnosed with EOCRC between 2000 and 2020, and we used spatial empirical Bayes smoothing to determine county-level hotspots. We identified 1,867 EOCRC diagnoses (52.7% in male patients, 69.2% in non-Hispanic White patients). Ten counties (34%) were classified as hotspots, with high EOCRC incidence or mortality. Hotspot status was unrelated to incidence rates, but non-Hispanic ethnic-minority men (incidence rate ratio, 1.49; 95% CI, 1.15â1.91), Hispanic White men and women (incidence rate ratio, 2.24; 95% CI, 2.00â2.51), and Hispanic ethnic-minority men and women (incidence rate ratio, 4.59; 95% CI, 3.50â5.91) were more likely to be diagnosed with EOCRC. After adjustment for income and obesity, adults living in hotspots had a 31% higher hazard for death (HR, 1.31; 95% CI, 1.02â1.69). Survival was poorest for adults with a late-stage diagnosis living in hotspots (chi square (1) = 4.0; p = .045). Adults who were married or who had a life partner had a lower hazard for death than single adults (HR, 0.73; 95% CI, 0.58â0.92). The risk for EOCRC is elevated in 34% of Utah counties, warranting future research and interventions aimed at increasing screening and survival in the population age 18 to 49.