Boy Scout geoscience education is not "desk" education--it is an informal, hands-on, real-world education where Scouts learn through activities, trips, and the outdoors, as well as in meetings and in the merit badge program. Merit badge requirements, many of which meet National Science Education Standards for Earth and Space Science, give boys foundational experiences and familiarity with geoscience topics. Earning a Geology merit badge at any location resulted in a significant gain of content knowledge (P < 0.001). The combined treatment groups for all location types had a 9.2% gain in content knowledge, but the amount of content knowledge acquired through the merit badge program varied with location. The longitudinal posttest scores, with a 15.0% increase from the attributed average pretest score, were higher than the posttest scores from any location except summer camp. No gains were seen in the control group; age and grade were not significant factors. Combining interview data with quantitative data indicates that Scouts who participate in the Geology merit badge are better prepared for school geoscience classes. Participation in the Geology merit badge provides geoscience experiences and "familiarity" with geoscience concepts that allow Scouts to create and retain geoscience knowledge.