No scheduled buses head in this direction. Route 931 -- which meets the Ring Road both 10km (6 miles) south of Egilsstaðir and 3km (1 1/2 miles) north of Egilsstaðir -- circumnavigates the lake, crossing a bridge near the southwest end. Route 933 branches off from Route 931 on both sides of that bridge, and forms its own loop via another bridge further southwest. Route 910 branches off from Route 933 (on the lake's northwest side) towards Snæfell, Kárahnjúkar, and elsewhere in the interior. Those headed directly from Egilsstaðir to Route 910 should take the north side of the lake for slightly less distance, or the south side for better roads.
This entire area is covered by the Egilsstaðir tourist information office. For Kárahnjúkar, the Végarður visitor center (tel. 471-2044; www.karahnjukar.is; Apr 27-Oct 15 daily 9am-5pm) is not directly en route to the dam: It's on Route 933 past the Route 910 turnoff. Ferðafélag Fljótsdalshéraðs (tel. 863-5813; email@example.com), which runs the Snæfell mountain hut, is the best source of information for hiking in the highlands.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.