Police are warning motorcyclists to be careful after two separate fatal crashes in one day in southern Alberta.

Richard Betts, 35, of Lethbridge, died when his motorcycle lost control at a turn and spun into a ditch on Highway 3, just east of Fort Macleod, on Wednesday night. His female passenger, 27, was taken to hospital with non-life threatening injuries.

The riders of a second motorcycle travelling with them were treated in hospital for minor injuries after they also failed to negotiate the turn.

RCMP investigators said speed was a factor in the crashes.

Also on Wednesday, Bruce Pearce, a high school principal from Regina, died in a motorcycle crash on Highway 9 near Drumheller.

Pearce was heading south down a hill when his motorcycle went out of control and landed in a ditch. He was taken to Drumheller hospital where he died shortly after, the RCMP said.

Riding courses advocated

The RCMP had issued a reminder last month about motorcycle safety as the number of those vehicles on the road increases in the summer months.

"Although speed and alcohol are often the root causes behind motorcycle collisions, inexperience is also a factor," said a news release from the force, advocating motorcycle driver training courses and proper safety equipment.

The Mounties encouraged motorcyclists to ride defensively, enhance their visibility, especially by staying out of drivers' blind spots, and to be alert at intersections.

The Bow Valley saw three deadly motorcycle crashes in June, including one where a rider ran into the back of a small SUV. Dax Carlson, 34, of Canmore, died of his injuries in hospital.