This mixed-methods study sought to identify professional development implementation variables that may influence participant (a) adoption of simulations, and (b) use for inquiry-based science instruction. Two groups (Cohort 1, N = 52; Cohort 2, N = 104) received different professional development. Cohort 1 was focused on Web site use mechanics. Cohort 2 was situated in nature and provided three additional elements: (a) modeling simulation use within inquiry-based instruction; (b) collaboration; and (c) provision of content-relevant lesson planning time. There was no difference in the extent of simulation use between cohorts, X[superscript 2](1) = 0.878, p = 0.349, f = -0.075. Results were inconclusive for a difference in observed inquiry instruction as Fisher's Exact Test was insignificant but had a medium effect size, p = 0.228, f = 0.283. Computer-based standardized tests emerged as a novel technology integration barrier. These findings have implications for school policy, professional development, and future research.