Despite the fact that they are all unique, rural school districts/divisions (in Canada and elsewhere) face similar challenges when it comes to providing effective professional development (PD) for teachers. Issues related to funding, geography, staffing, and contextual differences impact the availability of PD opportunities for educators in rural contexts; however, rural school divisions possess many strengths from which solutions to these challenges might be fashioned. The question of how rural divisions might construct local teacher PD models that draw on local strengths, mitigate local challenges, and support teacher professional growth is critical to the provision of quality education for rural students. Through a single-case study design, this study examined the effectiveness of a rural initiative, the Numeracy Cohort, that was locally constructed to mitigate challenges and improve mathematics instruction and student numeracy outcomes in a school division in Manitoba, Canada. Findings from the study suggest that (a) the Numeracy Cohort model was effective in accommodating contextual differences and mitigating challenges related to funding, geography and staffing through several promising practices; (b) the PD provided to teachers was effective in supporting teacher professional growth in several ways; (c) attention to the multiple nested and dynamic contexts in which teachers worked was an important and effective element of the model; (d) fostering social interaction (among teachers and with more competent others) was important for teacher learning; and (e) finding ways to foster human engagement through mediating tools for learning (e.g., dialogue, reflection, and action research) was critical to the model’s success.