re: How long to get the wall/barriers built?

There is also a unmanned border crossing in that area. All they have is a camera.

After crossing you need to self report.

I’m not for sure exactly where, but it is in a very rural area. A border patrol agent said most of the time it takes hours and sometimes more than 24 hours to get to some of these rural area’s.

No links. I saw this on TV a few weeks ago

ETA: Found this

Get ready for the very first "unmanned" border station on the U.S.-Mexico border. Slated to open at the end of this month, the Big Bend National Park in Texas will be staffed by, you guessed it, computers.

The station will be equipped with machines that can scan citizenship documents and conduct live video interviews with U.S. Customs and Border Protection agents at a station in El Paso, Texas, Tech News Daily reports. While Mexican citizens will be able to use the crossing, U.S. officials maintain that Americans tourists to the national park are more likely to do so. When a similar CBP crossing was open in the same location more than a decade ago, few Mexicans used it. In 2002, because of increased security measures, U.S. officials closed the original crossing, forcing tourists to travel more than 100 miles to the next nearest crossing to get to Mexico, according to Nextgov.

While similar unmanned border crossings are already implemented successfully on the Canadian border, this will be the first time a totally computerized station is built on the U.S.-Mexico border. Although this isn't exactly the first high-tech solution CBP has used to monitor the Southern border.