The majority of trail user data does not consider the environmental context perhaps impacting trail use. The purpose of this study was to analyze the potential link between contextual elements (e.g., seasonality, weather, physical activity (PA) intensity) and the PA patterns of trail users on a two-mile rail/trail segment via direct observation. The System for Observing Play and Activity and Recreation in Communities (SOPARC) was utilized to assess trail use. The PA level of each user is coded as Sedentary, Walking, or Very Active. Separate observations were made for females and males. Ambient temperature on the trail was also recorded. Observations took place four times a day (7:30am, 12:30pm, 3:30pm, 6:00pm) for 7-consecutive days. During the spring, summer and fall of 2006, (n=1,516) trail users were observed. A significant seasonality*gender interaction effect was found (F = 3.56; p =.028). More males were observed using the trail during each season. Significant gender differences in PA intensity were also found (F = 147.37; p =.000). Approximately, 72 percent (n=499) of females were walkers. However, only 25 percent (n=170) of females participated in vigorous PA in comparison to 58 percent (n=477) of males. As the temperature changed on the trail (F = 4.65; p =.000) so did the number of users. Approximately, 32 percent (n=478) of all users were observed between 71 and 80 degrees Fahrenheit; and over 50 percent (n=761) used the trail between 71 and 90 degrees Fahrenheit. Seasonality and ambient temperature were contextual variables linked to recreational trail use.