Glommen , the largest river of Norway, rising in the mountains of the S. E. part of the province of Drontheim, near lat. 63° N., and flowing for the most part nearly due S. through several lakes, into the Skager Rack. Its length is about 360 m. The entire valley through which it flows is remarkable for picturesque scenery, cataracts, and forests of pine, producing the finest timber in Europe. From the town of Roraas to the Ojeren lake, the river is a mountain torrent. The head of navigation is at Sarpsborg, about 10 m. from the mouth. The Glommen has more than 20 cataracts, the principal one being the celebrated Sarpfoss, half a mile above Sarpsborg. The river, a short distance above, is divided into two branches, which flow in parallel directions to the sea. The E. branch, having forced its way through a rugged defile, reaches the brink of a precipice, where, although divided at the summit by a projecting cliff, it falls an unbroken cascade, about 75 ft. The abyss is strewn with large masses of granite, which break the volume of water into vast sheets of foam. On the brink of the fall the stream is about 120 ft. wide, and from 26 to 30 ft. deep, according to the season.

The rapids, for a short distance inward, are remarkably fine.