Hugh B. “Trip” Ruckman III ’s family ties to the Karnes County National Bank date to 1901 when it started making loans to cattle ranchers and farmers in this rural community in South Texas. The mobile-home camps and sandstone-colored motels along Highway 181, where some rooms regularly cost more than high-rise hotel rooms in Houston and San Antonio, are newer additions to the local economy. So are the 18-wheelers that race down the streets and the mud-splattered pickup trucks that fill the Dairy Queen parking lot at lunchtime, their sides dotted with energy-company logos. Mr. Ruckman’s community bank doesn’t […]