In a post on Facebook, the event team said: "We are heartbroken to tell you that the 2019 Ard Rock enduro is cancelled.
"Flash flooding in the Swaledale valley has flooded roads, homes, land and submerged the Ard Rock site.
"Right now we are doing everything in our power to ensure our team on the ground is safe, and we can support all those who need help.
"The rainfall and situation is unprecedented in this area. Access to the area is blocked by emergency services from all roads. Please do not travel."
Businesses across North Yorkshire told customers they are 'still open' - despite the horrific weather.
The official Yorkshire Dales twitter account assured visitors not to 'cancel plans'.
In a thread posted this morning, they said: "As you may have heard, the Yorkshire Dales have been heavily affected by the flash flooding that occurred yesterday.
"Today and the days, weeks and months following, residents and local businesses will be dealing with the repercussions of this.
"If you have a trip booked to the Yorkshire Dales, don’t just cancel your plans, ring your accommodation, ring the local Tourist Information Centre and ask if they’re still open for business and how you can get there. They will be able to give the best advice.
"If you just cancel, all the local businesses will suffer, from the baker and butcher, to the local tearoom.
"This is meant to be the busiest time of the year for these businesses, whatever they make now, keeps them going through winter. They’ll need all the help they can get!"
Low Mill Guest House, based in Bainbridge, agreed with the advice.
They tweeted: "Our thoughts are with those affected by the floods but the Dales is open, the rain is temporary but the beauty and brilliance of the Yorkshire Dales and its people is permanent and not to be missed..no need for anyone to cancel their holiday."