This study is a secondary data analysis of data collected on preschool and kindergarten-aged children in Tulsa, Oklahoma in the fall of 2006 to study the effects of school and community-based public early learning programs on children's cognitive and social-emotional outcomes. Children in the study participated in the state-funded pre-k program, in the county Head Start (HS) program, or a combination of both. The present study aims to compare the overall effects of a high-quality state pre-k program and Head Start; compare the effects of different pathways into pre-k and Head Start; and to test whether two years of participation in public early learning programs (age three and age four participation) are more effective than one year (age four participation only). The overall sample includes 1,985 pre-k entrants; 739 HS entrants; and 4,121 kindergarten entrants (1,597 pre-k graduates; 474 HS graduates; and 2,050 who did not attend a public preschool program). The data come from four sources: direct cognitive assessments of children at the beginning of the school year; parent surveys collected at their child's cognitive assessment; social-emotional assessments conducted by each child's teacher; and administrative data from Tulsa Public Schools and Head Start. Using propensity-score matched groups, a regression discontinuity (RD) design was implemented to estimate program effects on outcomes at kindergarten entry. Findings show that while both pre-k and HS are effective at improving children's pre-academic skills at school entry after one year of participation, the high-quality Oklahoma pre-k program produces stronger gains in skills at the start of kindergarten than the Oklahoma HS program. Study limitations are discussed. Tables are appended.