FOUND!!!!!!!!!!! [Our travel trailer was stolen.]

Often times with GPS trackers you have to buy a box then pay a monthly or annual subscription fee. There's a much cheaper alternative. First you purchase a GSM GPS tracker box. It's essentially the internals of a cell phone in a box with a GPS antenna. You then purchase one of those prepaid/pay as you go SIM cards and insert it into the box. Whenever you need to track your property you just send a specific text message to the phone number tied to the SIM card. The GPS box receives the message then sends a text message back to you with its current coordinates. This is the same thing the subscription company does.

As long as the trailer is in GSM cell range, which covers about 95% or so of America, then it can be contacted. The only costs are the box itself and the prepaid SIM card. You could make that SIM card last forever since it's only gets used when you have to contact it. If you live in or frequent highly remote areas with no cell coverage then the more expensive VHF trackers might be a better idea. VHF units send out radio waves that police can follow with antennas. This is how LoJack does it.