2 UNION COUNTY PAST AND PRESENT or oil flows in considerable quantities. Other springs in the ` county possess chalybeate of line quality. Along the 36mile shore line of the Ohio a.re the river bottoms, a fringe of fertile fiatland. Not far from the shore the ground p rises, then dips; and inland from these ridges is a. succession of sloughs, ponds, and shallow lakes. Their alignment follows sub- stantially the curving eourse of the river, into which they cannot empty because of the higher ground nearer the rivers edge. ln some of the sloughs and ponds the water is stagnant, in others it is clear. Among them, Dixon and Harding Ponds and Geiger and Mortons Lakes are best adapted to swimming and boating.- ln places the strip of marsh land attains a width of more than three miles; but it narrows down to a quartermile at the down- stream end, near the Crittenden County line. Several of the sloughs hold water throughout the year. They range upward in size from small mudholes to small lakes and their total area is about 25,000 acres. When the hrst settlers came to Union County, they found cane _ growing in great abundance along the river front, furnishing a resort for flocks of passenger pigeons, wild turkeys, geese, and ducks, as well as for deer, otter, mink, wolves, wildcats, raccoons, and opossums. All these. common in the days when the great ornithologist, John James; Audubon, wandered through this region, have now disappeared. Gone are the passenger pigeons, once so numerous that Audubon on his way to Louisville from Hardinshurg, in 18].3, counted 163 flocks in twentytl1ree minutes. Gone. too, are the wild turkey, the prairie chicken, and the beautiful little Carolina parralceet. But most of the songbirds have increased enormously. These native to Kentuclay, as well as migratory birds wliieh follow the Ohio, Mississippi, and Ten- n<;ssc.-: Rivers are seen here in large numbers. li has been stated by the U. S. Bureau of Biological Survey that observers in these river valleys probably witness the passage of :1 greater number and variety of birds than in any other river valley in the world. Small mammals, including muskrats. squirrels, cottontails and marsh rabbits, raceoons. and opossums, exist in surprisingly large numbers. Occasionally mink and otter are seen. Several species of fish of the kind common to Kentucky, such as bass. crappie, jack salmon, and catfish are found in the lakes. ponds. and rivers. '