 SR 377 begins at an intersection with SR 195 in rural Lee County.It heads northwest, and curves to the north-northwest, to an intersection with SR 118, east of Smithville.The route continues to the north-northwest, crossing into Sumter County along the way, and meets its northern terminus, two intersections with US 280/SR 27/SR 30/SR 49, on one-way pairs, in Americus.