Descriptive statistics
Sociodemographics, COVID-19, stress, and sleep. There were no differences between groups in baseline sociodemographics. Reported experiences with COVID-19 are in Table 
COVID-19 related experiences of participants in Study 2Was not able to work due to COVID-19 illnessImpacts no participants endorsed across Studies 1 and 2 were: increased childcare costs, not enough money for rent or medications, no regular place to sleep. *In Study 2, COVID-19 related experience questions were asked at midpoint rather than baseline, as described in the textIntervention implementation. Twenty-two of 25 participants randomized to the intervention group signed up for the Western New York Winter Hiking Challenge. Of those who signed up, 54.5% completed at least 1 challenge hike, and 31.8% completed the challenge. Implementation data are in Table 
Intervention implementation and acceptability in Study 2Completed challenge hikes with(select all that apply):0.0% not enjoyable,16.7% moderately enjoyable, 83.3% very enjoyable*To date (the 2022 Western New York Summer Challenge was ongoing at the time of this writing)Intervention Effects on Hiking Frequency. There was a significant overall intervention effect on hiking frequency in the analytic sample (n = 47), such that the intervention group hiked more often than the control group overall (F = 4.23, p < 0.05; Cohen’s d = 0.60). There was also a significant change in hiking frequency over time (F = 3.63, p < 0.05), but no significant group-by-time interaction (p = 0.47). Group differences in least squares means at individual time points were not statistically significant at baseline or midpoint, with Cohen’s d values of 0.29 and 0.48 respectively, but were statistically significant by post-intervention (Fig. Intervention Effects on Sleep Duration, Sleep Quality, and Stress.There were no overall intervention effects on sleep duration (p = 0.12). However, overall mean differences were in the expected direction, corresponded to a Cohen’s of 0.45 overall, and reached trend level by post-intervention, such that the intervention group tended to have longer nightly sleep durations than the control group by the end of the study (p = 0.07; d = 0.55; Fig. With regards to stress, there were no statistically significant group, time, or group-by-time interactions, nor were the between-group comparisons of least squares means at each time point statistically significant, but magnitudes of the mean differences were in the expected direction, with increases over time (d = 0.07, d = 0.17, and d = 0.42 for between-group comparisons at baseline, midpoint, and post-intervention, respectively; Fig. 