A beef farmer from the bush has ridden his horse across the Sydney Harbour Bridge sending a message to the city about protecting the land.

Wearing an Akubra and a Driza-Bone vest, Glenn Morris from Inverell in north-west NSW saddled up his Australian stockhorse, Hombre, on Thursday morning.

Traffic slowed as Mr Morris trotted along lane eight of the bridge just after 10am.

"I'm sorry about that for anyone that was caught in the traffic, but I just had a message to deliver which I think was important," he told reporters afterwards.