276 
stream. ‘The sand and gravel of Prairie Creek valley, probably repre- 
senting the terrace, as shown in the Prairieton section. The section on 
the south county line shows three miles of flood plain east of the river. 
This plain is low along Prairie Creek and is crossed by a low, rocky ridge 
near the bluffs. West of the river the terrace is about two miles wide, 
with an average elevation of about 35 feet above low water in the river. 
S75 BEER LA BY ie 
