This is a fantastic, authentic 19th Century large Northern Plains dag knife paired with a beaded sheath, both attributed to the Sioux. The dag knife, likely from the mid-1800’s, shows a classic beaver back or beaver tale design with large and long hand sword like forged blade with double edge and median ridge running down the center of both sides. The blade edges go in slightly at the bellow and taper slightly out at the end, a unique pattern. The handle shows one piece hardwood handle with half circle “D” paddle hilt with rounded handle and raised band pommel end with slightly rounded end that is covered in a band of brass covered metal tacks. The handle is wrapped in parfleche rawhide. The one piece handle is held into place with two larger iron rivets at the top and overall has a rich dark original patina. The wood shows signs of old blacksmith file brandings. The back side of the blade is stamped “IS” which is believed to stand for I.S. Sorby by previous collectors but also could be Indian Service or another blacksmith touch mark. The knife is paired with a beautifully beaded sheath in typical “Sioux” pattern dag sheath pattern. The piece is comprised of Indian brain-tanned buffalo / bison hide being sinew sewn and linted with parfleche rawhide and adorned along the front with elaborate wonderful beadwork in geometric form with Indian hide fringes along the bottom having solid brass trade beads and rolled tin jingle dangle cone ends. The beadwork shows a corn yellow / greasy yellow background with pattern in red white heart, chalk white, medium light blue and a bright royal blue, all of which are glass trade seed beads sinew sewn. Several Northern Plains and Sioux pattern beaded dag sheaths show a more rectangular shape, unlike the often seen Blackfeet pattern with tapering foot and diamond drop along with bead free midsection. The knife is an early, rare example likely dating to circa 1800-1850 and has an IS touchmark, thought by the collector to be I.S. Sorby (as there are other I.S. Sorby documented examples in similar fashion from John Baldwin, Hanson, etc..) put could be a later addition. It is paired with a nice classic pattern beaded Buffalo hide and parfleche lined sheath. Provenance: From the Dale Harrison Cincinnati, Ohio collection. Knife measures 14 3/8”L by 2 5/8”W. Sheath is 17.25”L by 3.25”W.