Border Patrol keeps watch on the Hi-Line

Sudden gusts of wind toss the tiny single-engine, four-passenger plane as it crosses the Hi-Line sky. It is 10 a.m. on a Friday morning, and Border Patrol pilot Joe Mulhern is flying a Cessna 182 aircraft on his daily patrol along the U.S.-Canadian border.

Takeoff was silky smooth in the hands of talented veteran Mulhern, who began flying when he was 16. The closer the plane flies to the Sweet Grass Hills, however, the less predictable the wind becomes. Gusts exceed 50 mph, and the plane is more or less at the mercy of the elements.

"Nature is more powerful than anything man can make," Mulh...