Click "show more" for time stamps, links and discussion:

New, easier method here:    • RDR 2: Horseman Challenge 9 as Arthur...  
NB: If you are following my 100% completion guide, you can do this challenge in the Epilogue and it will be much easier. This is optional for those who want to complete as much as possible as Arthur.

0:00 Introduction

Guide
1:10 Preparation checklist
3:08 Preparation part 1 buy a Dutch Warmblood
3:47 Preparation part 2 how to practice the jump
4:38 5:21 MOST IMPORTANT TIP: how to take the jump
7:24 Preparation part 3 stock up on health items, and how to deal with the Pinkertons

Horseman Challenge 9 Full Run, as Arthur in Chapter 4
9:33 Horseman Challenge 9, with map route set for first leg [Start]
10:34 Cut across to the railway track to the west, then head south until you rejoin the red route
13:28 Set the map route for the second leg, and then follow the route down the railway track, following the trainline northwest from 14:05
15:03 Keep following the train track taking the left hand fork
16:37 Move around the train and rejoin the red route
17:13 Set the map route for the third leg
17:33 Make sure your favourite weapon is ready I favour the Bolt Action Rifle with express rounds
17:59 Brush and feed the horse, and eat minty big game
19:00 Make the jump
19:13 Set the map for the final leg
19:40 Spotted by Pinkertons
20:24 Flee to the finish line
20:43 Horseman Challenge 9 [Complete]
21:00 Escape to the north east
21:30 Lose wanted level back in Big Valley after fording the stream

See at the bottom for links to my full 100% completion guide. The last two Herbalist and Horseman Challenges are difficult to get before the epilogue, but see these video guides if you want to get the Legend of the East Outfit early:

How to complete Herbalist Challenge 9 as Arthur Morgan:
   • RDR 2: How to complete Herbalist Chal...  

How to complete Herbalist Challenge 10 as Arthur Morgan:
   • RDR 2: How to complete Herbalist Chal...  

How to complete Horseman Challenge 10 as Arthur Morgan:
   • RDR 2: How to complete Horseman Chall...  

Click here for the full 100% completion playlist, including optional side activities:
   • RDR 2: 100% Walk through plus optiona...  
Click here for the full 100% completion strategy guide:
https://gtaforums.com/topic/922595rd...