WISCONSIN (CBS 58) -- State officials are urging snowmobile riders to drive safe after three deaths over the weekend.

That brings the total number of snowmobile deaths this season to 17.

Nine of those deaths happened in February.

There were 16 snowmobile deaths last year. 

The DNR says there's a concerning trend when looking at the data for these crashes.

"The data shows that speed and alcohol tend to be contributing factors in a majority of those cases," said Lt. Martin Stone. "Gotta slow down, and zero alcohol -- don't drink before or during a ride."

Officials also encourage riders to carry a first aid kid, cellphone, stay on marked trails and avoid frozen waterways.

They recommend you never travel alone.