Total wells drilled (906) in Nebraska during 1960 represented a 5% decrease from 1959, although exploratory drilling increased 6.1%. Success ratio for wildcat wells was 10.4%. Most significant were 6 new fields discovered on the west flank of the Cambridge arch, where in addition to Lansing-Kansas City production, "Reagan" sand (Cambrian (?)) was found productive at Sleepy Hollow. Total production in western Nebraska for 1960 was 23,921,487 bbls., an increase of 5.9% over the 22,584,096 bbls. produced in 1959. The Denver basin production increase amounted to only 2.6%, whereas Cambridge arch production increased over 806%.

Drilling in Colorado totaled 703 wells, a decline of 16.1% from 1959. Exploratory drilling in eastern Colorado decreased 76.7%, while wildcat wells in western Colorado increased 11.8% over 1959. Success ratios for the two areas were 11.9% and 16.7%, respectively. Foremost in importance was the discovery of gas and condensate from the Mississippian and Devonian rocks at Southeast Lisbon in the Colorado part of the Paradox basin. Six gas fields and two oil fields were found in northwest Colorado, including a significant Weber (Pennsylvanian) discovery on the Danforth Hills anticline and several Cretaceous Mancos-Mesaverde transition zone gas discoveries. Total production in Colorado for 1960 was 47,427,297 bbls., a 2.1% increase of 973,885 bbls. over the 46,453,412 bbls. produced in 195 .

Geophysical activity increased sharply on the Cambridge arch, south-central Nebraska, and in the Paradox basin of southwest Colorado, the latter area accounting for 54% of total seismic work in Colorado and Nebraska. These same areas provided the most active regions, leasing and trading-wise.

The decline in Denver basin Cretaceous exploration, which was sharply down in 1960, is expected to continue during 1961. However, this will undoubtedly be offset by continued increased activity in western Colorado and on the Cambridge arch of south-central Nebraska.

Changes during 1960 in the Mineral Leasing Act involving increased annual rentals of Federal lands will probably cause a more rapid evaluation of such lands during 1961.