We are in a state of war.....so your GPS will be off as much as 50 ft......we don't want terrorists stuffing a missile guided IED in your back pocket...
I've been along the NV-UT border quite a bit and my GPS is within plus or minus 20 feet of the stateline markers and the border depicted on google earth. To my knowledge none of the handheld GPS units guarantee any accurance less than that.
Check you datum settings against the maps and GoogleEarth. Sometimes the GPS settings are on NAD27, when, I believe, GoogleEarth and newer maps are on WAGS84...refers to when the coordinates were developed