Lake Kvíslavatn north, is on Arnarvatnsheiði, 4 km northwest of Úlfsvatn. It is 2.6 km² in area, shallow and at 429 m above sea level. Urðhæðarvatnslækur flows into the east side of the lake and from the lake flows Kvíslavatnskvísl through Skjaldartjörn and Skjaldartjarnarkvísl to Kjarrá. This is a fine fishing lake with good size fish, both char and brown trout. There is evidence that salmon from river Kjarrá have migrated into the lake, as several kelts have been caught.