The Pioneer Woman's Grave is located near Barlow Pass, Oregon.  This unknown woman was one of many who had journed from the east across the Oregon Trail en route to Oregon City during the mid-19th century & made it just short of reaching her goal.  From the nearby sign:

In 1924, engineers constructing the first Mt. Hood Highway discovered a gravesite here.  The grave was marked with an old wooden wagon tongue buried beneath decades of overgrown brush.  When they dug up the site, they found the remains of an emigrant woman.  After reburial, a cross was placed in honor of this unnamed pioneer. 

The son of Steven Coalman (former Barlow Toll Road Superintendant) recalls: "My father remembered meeting a man who had just buried his wife.  He buried her in a wagonbox made of the wagon, and made a crude fence around the grave.  She had been very sick, and they had camped there several days before she died.  The man had two small children, a boy and a girl, both under five years of age."