Getting There -- Þórsmörk is accessed via Route 249/F249, which proceeds 30km (19 miles) east from the Ring Road along the southern edge of the Markarfljót Valley. Only 4WD vehicles with good clearance can reach one of Þórsmörk's three accommodations (Básar), and possibly another (Skagfjörðsskáli), though it's often safer to park and walk the final kilometer by crossing a pedestrian footbridge a short ways downstream. Even 4WD vehicles should not drive directly to the third accommodation, Húsadalur; drive to Skagfjörðsskáli (or the pedestrian bridge) and walk the 30 to 45 minutes to Húsadalur from there.
From June 1 through September 10, Reykjavík Excursions (tel. 562-1011; www.re.is) has a daily bus that leaves Reykjavík at 8:30am and arrives at Húsadalur at noon, with stops in Hveragerði, Selfoss, Hella, and Hvolsvöllur. (The bus is cancelled only two or three times a year in response to surges of glacial meltwater.) At 1pm the bus leaves for Básar, arriving at 1:30pm and then continuing to Skagfjörðsskáli (called "Langidalur" on the schedule). The bus returns to Húsadalur at 2:30pm, and leaves for Reykjavík at 3:30pm. From June 15 through August, every day except Sunday, a second excursion bus leaves Reykjavík at 5pm and arrives at Húsadalur at 8:15pm, returning to Reykjavík at 8:30am the following morning without stopping at the other lodgings. A one-way adult ticket from Reykjavík to Þórsmörk is 3,900kr ($62/£31).
Visitor Information -- For general information, contact the organizations running the accommodations. An excellent hiking map, Þórsmörk og Goðaland, is for sale at all the huts. An only slightly less detailed map can be downloaded free from www.thorsmork.is.