Exploration in Pennsylvania during 1961 resulted in the discovery of 4 new gas fields, 6 new gas pools, and 2 deeper gas pools. Also several fields and pools were extended, The outstanding discovery was the Whippoorwill field in Cameron County on the SE. flank of the Sabinsville anticline. Other important discoveries were the Pavia field in Blair and Bedford counties, the Spruell field in Fayette County, the Brooky pool in Crawford County, the Lundys Lane pool in Erie County, and the Bailey and Clarke pools in Westmoreland County. The greatest density of deep drilling (Middle Devonian or older) occurred in Crawford County where 21 wells were drilled. Armstrong County again had the greatest number of shallow-sand completions (Upper Devonian or younger) outside of the secondary-recovery areas with the drilling of 46 wells. No new shallow-sand field or pool was discovered during the year. During 1961 there were 679 new wells drilled and 30 wells deepened. Of the 679 current-year completions, 642 were in proved fields, and 37 were exploratory tests. Of the 642 proved field wells, 211 were oil, 182 water input, 172 gas, 8 gas input, 10 gas storage, and 59 dry holes. Of the 211 oil wells, 168 were drilled in connection with secondary-recovery operations. Of the 37 exploratory tests, 12 were gas, and 25 were dry. Of the 311 completions drilled outside of underground gas storage or secondary-recovery operations, 84 were dry, a dry-hole ratio of 1 in slightly over 3.7. The total footage drilled during the year was 1,722,955 ft. Exploratory tests totaled 37, drilling a total of 224,615 ft. of hole, or an average per well of 6071 ft. Of the 37 exploratory tests, 12 were successful and 25 were dry, giving a success ratio of 1 in 3.1 or a failure ratio of I in 1.5. Oil pipeline runs totaled 5,580,000 bbls., or a decrease of 6.1% from the 1960 figure of 5,942,000 bbls. Proved oil reserves as of Dec. 31, 1961, were estimated at 102,448,000 bbls. Gas produced totaled 98,318,000 MCF as compared with 119,671,000 MCF in 1960. Gas reserves were estimated at 1,168,853,000 MCF at the end of the year. The total reservoir capacity for the storage of natural gas in Pennsylvania is 511,700,000 MCF. The total acreage held by major oil and gas companies for deep oil and gas exploration in Pennsylvania amounted to approximately 3,649,000 acres at the year's end. Numerous geological field parties were active during 1961. Seismic crews logged 133 weeks in the state. This is an increase of about 28% over the seismic activity shown in 1960.