Smjörfjöll, (“Butter mountains”) between Vopnafjörður and Jökulsárhlíð, steep and rocky on the Vopnafjörður side. Mostly 1,200 m high, the highest 1,251 m. Little vegetation, rough and much scree, some rhyolite. Snowdrifts all summer in many places. Various streams become difficult to cross during thaws, though there is usually little water in them at other times.