One of our customers in Durango Colorado has to use snow stakes on a 4 mile lot. This lot is at 9000 feet elevation with about 50 hair pin turns. Needless to say it is extremely important to have high quality reflective markers on the road.
Colorado obviously has heavy snow fall so making sure roads are staked properly can mean the difference between safety and potential disaster. In this pic you can see how effective our snow stakes are at guiding the way on the road. 
Check out the video of the road. Tons of snow, tons of stakes. Stay safe in Durango.