U.S. authorities took time to construct barriers to those routes, forcing travelers to seek other paths to get to the U.S., which means they were fed back into more dangerous areas, more treacherous conditions, and of course, more people started dying as a result.
The numbers are never really publicly acknowledged, because they are horrid, and some bodies are simply lost in the desert completely, and never counted.
There are US racists who make a point of going into the desert to look for the small stashes of water bottles conscientious US Americans take out there, hoping to leave them for the struggling travelers to find, hoping to help. The haters always destroy the bottles when they find them, of course.
We can only hope good people outnumber the monsters out there!
Here's a quick google grab which might be illuminating, have to underscore official records are always well under the actual number of lives lost each year:
How many people die crossing the US-Mexico border?
Fleeing violence and poverty, thousands of migrants from Central and South America make the long and dangerous journey from Mexico to the United States every year. Hundreds perish in the process.
Published on Tue, October 25, 2022 3:32PM PDT | Updated Mon, December 12, 2022 3:37PM PST
Since 1998, at least 8,000 undocumented migrants have died attempting to cross the border from Mexico to the US. Their journey often involves traveling through desert areas where theres few sources of water, steep rocky terrain, and temperatures reaching 118°F during the summer.
Extreme heat, drownings, and falls are some of the frequent causes of death for those trying to cross.
According to Customs and Border Protection (CBP), violence, poverty, and economic insecurity are the factors driving unprecedented levels of migration to the US-Mexico border.
While thousands of migrants at the border apply for asylum in the United States every year, the vast majority of applications go unapproved. In 2021, 670 out of 14,361 applicants, or 4.7%, with a Mexican nationality were granted asylum.[1]
What does the US-Mexico border look like?
The US-Mexico border spans 1,951 miles. It cuts across the Sonoran Desert, which covers parts of Mexico, Arizona, and California, the Chihuahuan Desert, which covers Mexico, New Mexico, and Texas, and the Rio Grande River, which divides Texas and Mexico.
More:
https://usafacts.org/articles/how-many-people-die-crossing-the-us-mexico-border/