The State of Iowa's Department of Natural Resources has a Healthy and Happy Outdoors (H2O) program for ages 10 and up. By logging outdoor activity at the H2O webpage, participants enter a giveaway. Each activity logged equals one entry. Giveaway prizes are varied and given at different times during the year. Why not try to get a prize for spending time outdoors with an activity you love?
Participation requires creating a free account with the state, then logging activities by the type of activity and amount of time spent. Here's a screen shot:
There is a box in the sidebar that incentivizes you by counting the days left until the next giveaway.