What Is The U.S. Border Patrol Doing on Highway 53 in Wisconsin?

Several times during the last few weeks, I've spotted a parked U.S. Border Patrol vehicle parked behind a huge snow drift near the 53 and highway 2 cutoff. The vehicle was running, and looked to me as if they were perhaps looking for someone in much the same way as the State Troopers look for speeding vehicles. During the summer months, I would see the Border Patrol maybe three or four times, but it seems they've stepped up their presence as of late. 

Having had a very unpleasant experience at the Canadian border once myself (I was detained and questioned for four hours, my vehicle torn apart, and suitcase contents thrown on the ground and gone through, then left for me to clean up the mess after I was free to go) I know these folks mean business. It seems strange to me they would choose such a "hidden" spot, repeated times, if they weren't on to something.

I've pretty much come to the conclusion they are looking for someone or something. Perhaps some sort of surveillance, or maybe they just want their presence shown (but I doubt that because of where they park.)

If you care to share your thoughts as to what's going on, feel free. I will stay on this, perhaps even giving them a call. Heck, I might even stop and talk to them the next time I see the vehicle. If you see a suitcase and clothes strewn on highway 53 some morning on your way to work, you'll know whose it is.