Dartmoor National Park Guided walks
http://www.dartmoor-npa.gov.uk/vi-eventsguidedwalks.htm
Volunteer opportunities
Okement Rivers Improvement Group
The group meets on the last Saturday in each month to clear rubbish from the rivers and litter from the river banks and carry out light coppicing and brush clearance along riverside walks.
http://www.okehampton.gov.uk/index.php/community-groups/127-okement-rivers-improvement-group
Sticklepath and Okehampton Conservation Group
Various events throughout the year
http://www.dartmoor-npa.gov.uk/vi-volunteering_stoc.htm