Loads of tours visit the falls, but in summer 2018, public buses were cut completely. Check the park website, local tourist offices or www.publictransport.is for the latest news.
Things will almost certainly change when Rte 862 is fully sealed.
Dettifoss can be reached three ways in summer by car – and only one way in winter (with no guarantee of access). Verify road openings at www.road.is.
- Rte 862 north from the Ring Road The turn-off to Dettifoss is 27km east of Reykjahlíð (Mývatn); it’s then an easy 24km on sealed road to reach the falls. Note that snowfall may close this road in winter, thus winter road access is not guaranteed. You can join a super-Jeep tour from Mývatn to see the falls when the road is closed.
- Rte 862 south from Ásbyrgi (37km) At the time of writing this route was slowly being sealed, in stages (the northern 16km are expected to be sealed by the end of summer 2019). Check locally about its condition. It's open from about June to early October (weather dependent).
- Rte 864 on the eastern side of the river It's gravel for its 60km length, from the Ring Road to Ásbyrgi. It's not an F road (ie for 4WDs only), but it can be tough going in a 2WD. Route 864 is open from about June to early October (weather dependent).