Undergraduate research education occurs in a variety of formats including co-curricular, summer internship, and course-based formats. Research on such programs historically focuses on undergraduate outcomes particularly in STEM disciplines. Situated learning theories such as cognitive apprenticeship and community of practice feature in exploratory research on how research is associated with participant learning. However, there is a lack of practical research on the role of undergraduate research experiences as situated learning and on the type and implementation of practices associated with undergraduate research program delivery, particularly in natural resources disciplines. Understanding the roles of such mechanisms in providing the broad range of benefits to undergraduate and mentor participants is an area of further exploration. This research describes undergraduate research experience programs, associated outcomes, and outcomes' relationships with situated learning elements. The first research chapter sampled program coordinators using researcher-led respondent driven sampling and describes the population of natural resources undergraduate research experience programs during 2012-2016 across 127 such programs. Two-step cluster analysis using program characteristics identified seven variables that distinguish between seven program types. Variables included pay amount, academic preparation activities, graduate student mentorship, highest student classification allowed, affirmative action statement presence, undergraduate cohort siting, and summer duration. Program types were underclass intensive traditional, extended graduate student mentored, professional development, distributed intensive, site-based traditional, shorter duration intensive, and larger long-term types. The next research chapter explores how undergraduate participants in a subset of natural resources research experiences viewed their programs as situated learning and outcomes attributed to their experience. Exploratory factor analysis identified six situated learning domains associated with the practice of undergraduate research in natural resources disciplines: effective mentorship methods, project and task sequencing, mutual engagement, broad repertoire, specific repertoire, and joint enterprise. Outcome factors indicated moderate to strong gains in the following areas: general skills, career trajectory, academic and career readiness, communication of science, cognitive skills, and researcher identity development. Effective mentorship methods, sequencing, broad repertoire, and specific repertoire were significant predictors of increased gains across all outcome factors. The final chapter is a mixed-methods case study evaluation of a postgraduate mentored research experience program titled PINEMAP Fellowship. Participant outcomes associated with the fellowship lend support to prior literature on how participants, particularly a set of demographic groups, benefit from participation. Findings offer empirically-based considerations for program developers and coordinators in promoting and adapting programs to undergraduates' needs and goals as well as provide suggestions for further analysis of causal relationships. Additional research is needed to explain how and to what degree undergraduate experiences in natural resources and other disciplines provide positive outcomes for a diversity of participants. / Doctor of Philosophy / Undergraduates as part of their education may conduct research with faculty and graduate students, and students generally experience many different benefits from research participation. For example, a student may individually work with a research mentor during the academic year, or groups of students may work with several research mentors over the summer, and in some courses taken for credit students may conduct research-related activities. Research on summer-based programs varies greatly and typically focuses on undergraduate outcomes in science, technology, engineering, and mathematics disciplines. Studying these types of programs and their participants' outcomes is difficult and some areas have been understudied, particularly in natural resources disciplines. Further, there is a need to understand which kinds of training practices identified in theory provide the broad range of benefits to undergraduate and mentor participants. This research describes the variation in natural resources undergraduate research experience programs, and it suggests how undergraduates may benefit from participating in these programs. One chapter describes an estimate of the size and types of summer internship-style natural resources undergraduate research experience programs operating from 2012 to 2016. Surveys indicated 127 programs operated during that time and could be classified as either underclass intensive traditional, extended graduate student-mentored, professional development, distributed intensive, site-based traditional, shorter duration intensive, and larger long-term types. Program types were identified with seven important variables: pay amount, academic preparation activities, graduate student mentorship, highest student classification allowed, affirmative action statement presence, undergraduate cohort siting, and summer duration. Another chapter explores how undergraduate researchers in natural resources experienced a range of teaching and social learning practices including mentor's teaching practices, how learning activities were sequenced, engagement with others, general information and tools, project-specific information and tools, and research community purpose. Undergraduates also reported gains in general skills, career trajectory, academic and career readiness, communication of science, cognitive skills, and researcher identity development. Mentor teaching practices was an important factor in predicting how much students benefitted in each outcome, and most practices were associated with other outcomes. The last research chapter used different methods to evaluate the PINEMAP Fellowship program. Undergraduates experienced a variety of gains, particularly in communication skills, although generally their attitudes toward research did not change. Mentors in the program also experienced work-related, social and emotional, interpersonal, professional, and thinking skills gains. PINEMAP Fellowship participants' data supported other studies' findings on how participants, and particularly some demographic groups, benefit from participating in undergraduate research programs. Altogether, this study offers considerations for program developers and coordinators in promoting and adapting programs to undergraduates' needs and goals as well as provides suggestions for deeper analysis of how participants obtain their gains. Further research is needed to explain how and to what degree undergraduate experiences in natural resources and other disciplines provide positive outcomes for a diversity of participants.