How many feet on the ground equal one inch on this map? I measured the river distance from Dunning Slough down to Ord Ferry Road and got 20.23". How many feet long is this stretch of river? D. I...

How many feet on the ground equal one inch on this map? I measured the river distance from Dunning Slough down to Ord Ferry Road and got 20.23". How many feet long is this stretch of river? D. I measured the straight line distance on the map and got 9.89". How many feet long is the straight line distance?