There are still samaritan communities in israel. The encyclopedia judaica outlines the popular view of their origin and history here:

Until the middle of the 20th century it was customary to believe that the Samaritans originated from a mixture of the people living in Samaria and other peoples at the time of the conquest of Samaria by Assyria (722–721 BCE). The biblical account in II Kings 17 had long been the decisive source for the formulation of historical accounts of Samaritan origins. Reconsideration of this passage, however, has led to more attention being paid to the Chronicles of the Samaritans themselves. With the publication of Chronicle II (Sefer ha-Yamim), the fullest Samaritan version of their own history became available: the chronicles, and a variety of non-Samaritan materials. According to the former, the Samaritans are the direct descendants of the Joseph tribes, Ephraim and Manasseh, and until the 17th century CE they possessed a high priesthood descending directly from Aaron through Eleazar and Phinehas. They claim to have continuously occupied their ancient territory and to have been at peace with other Israelite tribes until the time when Eli disrupted the Northern cult by moving from Shechem to Shiloh and attracting some northern Israelites to his new followers there. For the Samaritans, this was the "schism" par excellence.

— "Samaritans" in Encyclopaedia Judaica, 1972, Volume 14, col. 727

Today Samaritans practice a religion known as Samaritanism which uses a slightly different version of the pentateuch than mainstream judaism.

I've only read excerpts from this source but if you're interested in samaritan history, The Keepers: An Introduction to the History and Culture of the Samaritans, by Robert Andersom, seems like a good place to start.