TIOGA, county of Pennsylvania, bounded E. by Bradford county of the same state; S.E. and S. by Lycoming; W. by Potter, and N. by Steuben county, New-York. Length from east to west 36, mean width 32, and area 1152 square miles. Ex tending in Lat. from 41° 32' to 42°, and in Lon. from 0° 04' E. to 0° 40' \V. from the meridian of IV. C.
The surface of this county is composed of two inclined planes, the separating ridge or summit level extending from north%t est to southeast. From the southwestern declination flow Pine Creek and Lycoming Creek, southwardly into the West Branch of Susquehannah river, and from the north western slope flow the various sources of Tioga river. The surface is broken, hilly, and partly mountainous, and may be regarded indeed as a new settlement, as in 1820 the population was only 4021, whilst in 1830 the inhabitants amounted to 9074, having gained 125 per cent in ten years.
By the post office list of 1831, besides Wellsbo rough, the county seat, there were post offices at Bloomsbury, Covington, Crooked Creek, Daggett's Mills, Dartmouth, Elk Land, Ingham, Knoxville, Lawrenceville, Liberty, Mainsburg, Mansfield, Nelson, Pine Creek, Rutland, Sullivan, Tioga, and Westfield.
Wellsburg, the county seat, is situated on or near the head of a small branch of Crooked Creek, Branch of Tioga, about 50 miles a little W. of N. from Williamsport, on the west branch of Susque hannah river, about 100 miles, following the road northwestward from Wilkesbarre, and by post road 147 miles a little IV. of N. from Harris burg, and 253 miles in a nearly similar direction from W. C. As laid down in Tanner's Pennsylva nia, the latitude is 41° 44' N., Lon. 0° 36' IV. from W. C.