You need a Utah attorney to deal with this. Use Avvo attorney search to find one.
ANDREW ROBERTS CRIMINAL AND TRAFFIC TICKET DEFENSE ATTORNEY
You can most likely hire a local attorney in Utah to represent you, without you needing to appear. Find an attorney in the municipality in which you received the ticket, and give them a call.
Hire an attorney in Utah who specializes in traffic tickets and who regularly appears in the court where your case is venued. As to fighting this, I would say it will be tough, as you all but admit that you were not observant of the speed limit changing. Was the sign stating the 40 mile per hour limit obscured by trees? Was it knocked down? Was there even such a sign or paint on the road giving you notice to slow down?