Exploration and development drilling during 1961 within the 25,000 sq.-mi. Railroad Commission District 3 of Texas is covered in this report. Exploratory drilling during 1961 showed a slight decline over 1960, there being 4 fewer wildcats drilled. Development drilling showed a 16% increase over 1960. Principal wildcat activity was along the Frio trend, accounting for 55% of the new-field discoveries and 54% of the wildcat dry holes. The Cretaceous trend was given the most attention by geophysical crews. Lease activity along this trend indicates that prospecting by the drill will be accelerated in the future.