When did slacklining start?

Related questions

1. What is Slackline made of?
2. How tight should a slackline be?
3. What is the highest successful tightrope walk ever?
4. How wide should a slackline be?
5. How long does it take to learn to slackline?
6. What does a slackline do?
7. What is walking on a rope called?
8. Do slacklines damage trees?
9. How big is a tree slackline?
10. Why do we hold our arms out to balance better?

Tags

1. #began
2. #yosemite
3. #1980s
4. #founders
5. #sport
6. #became
7. #grosowsky
8. #ellington
9. #climbers
10. #originated
11. #national
12. #modern
13. #slacklining