For a few miles, this border city is separated from Mexico's much larger city of Juarez by two tall fences on the US side of the Rio Grande. There are no fences on the Mexican side of the river.
On a recent morning, just as this reporter was passing by, three men in work clothes ducked through large holes in both fences, looked around, then ran across a highway into an El Paso neighborhood of small apartments.
The illegal-alien population in the United States had just increased by three. Within a few minutes two more men ducked through the same holes and entered the United States. With only slight variations (some illegals walk around the end of the fences) the scene is repeated almost hourly, all year round.
Many who cross illegally work, shop, or visit in El Paso, then return in a few hours or days to their homes in Juarez. Others go far into the US - mostly to California and Texas - for jobs. And they, too, generally return to Mexico part of the year.
US Border Patrol agents say the holes in the fences actually make it a little easier to catch some of this daily flow of people, by funneling it through a few points.
But fences guard only a few miles of the nearly 2,000-mile US-Mexican border. And the famed Rio Grande is usually dry or only a few inches deep and is so narrow in places that you can easily throw a rock across it.
Typically, the US-Mexican border is nothing but wide-open stretches of desert. Yet most crossings are made in the urban areas, since it is easier for the illegal crossers to blend in quickly with legal residents. Some who cross regularly into El Paso then catch buses to work. They are international commuters - illegal ones.
The penalty for getting caught is minimal. Unless a person has been caught many times before, he or she is detained for only a few minutes or an hour or so , then released just across the border. Most turn right around and sneak back in.
''Some are caught again within a half hour,'' says one Border Patrol agent here. But most are not caught. When caught, the illegal aliens are generally polite, sometimes smiling, and the officers arresting them are similarly polite.
''They know it's a game, basically. As a rule we don't have any problems,'' says Border Patrol agent Gary Runyon. ''That could change if we did something to punish them,'' he adds as we cruise downtown El Paso streets and the border, looking for ''wets'' as the agents call those who cross illegally.
There can be an edge of violence to the ''game.'' Agent Runyon says he has had as many as 200 men at one time trying to come through an illegal entry point when he was patrolling the point alone. Some of them threw things at his car.
Occasionally someone drowns crossing the canal that parallels the Rio Grande here or gets hit by a car while trying to dart across a border highway without being spotted.
Sometimes the illegal aliens are victims of ''rapes, cutting, and shooting'' on both sides of the border in unlighted areas at night, agent Runyon says. ''We get everything.''
Some US employers play a part in the illegal border-crossing ''game.'' They pay a contact to smuggle undocumented workers to US jobs, according to the Border Patrol. Smugglers have been found driving trucks, jeeps, and motorcycles across unfenced areas. Often their night scopes, radios, and other equipment are more than a match for the Border Patrol.
Sometimes smugglers stuff illegal aliens into the trunks of vehicles - where some suffocate - or squeeze groups of them into vans or trucks for long journeys without food or water.
Some of El Paso's legal residents also play a part in the ''game.'' Many families here employ Mexican maids and babysitters who work here illegally during the week, returning to Juarez for the weekends. One Mexican-American here says the illegal maids are often paid as little as $25 a week. If they were paid more, the women in families hiring them could not afford to go out and find a job themselves.''
We cheer when they make it across'' the border, says the daughter of one affluent American family here.
Many area employers in construction and other work hire illegals - knowingly or not (or not wanting to know) - often at rates lower than most legal residents demand.
In El Paso there seems to be less concern about undocumented workers than expressed by some nonborder-state politicians.
But there is some concern that the children of illegal aliens are putting an unfair burden on the public school system and that illegals may be straining other local services. And on a recent local roundup of some 700 illegal aliens by the Border Patrol, some 331 were found to be working at wages ranging from $2 to $8.75 an hour.
Since his recent arrival here, acting chief Border Patrol agent Jack L. Richardson has boosted morale among the agents by organizing several other major operations. These have included the arrest of 59 accused smugglers of illegal aliens and a recent sweep of many of El Paso's bars and nightclubs, which netted nearly 800 arrests, including many barmaids and entertainers.As usual, the arrested were quickly let go just across the border. Agents speculate that most were back at work the next night - or even later the same night.
Several years ago, Mexican illegal aliens were deported to their home area to try to discourage them from returning to the United States. But the results of this experiment were ''inconclusive,'' says a spokesman for the Immigration and Naturalization Service in Washington.
The experiment was ended.The border control and deportation policies now in effect, which are clearly ineffective, appear to reflect a political compromise between the positions of those advocating a ''closed'' border and those who contend that the US needs many of the undocumented workers to do work Americans will not do.''
The border is controllable,'' chief Richardson said in an interview. Others disagree.The border cannot be controlled ''except by having soldiers every 20 feet,'' says Ellwyn R. Stoddard, a border studies specialist at the University of Texas at El Paso.
Although the greatest number of arrests are made right along the border, checks at the El Paso airport and on highways leading into the surrounding desert are very productive, according to the Border Patrol. Ground sensors developed for use in Vietnam are used in the desert to detect foot traffic.
El Paso is the second busiest illegal crossing point after the Tijuana-San Diego area. Arrests by the El Paso Border Patrol have increased from about 51, 000 in 1970 to about 150,000 in 1981. Whether this increase reflects an increase in Border Patrol efforts or an increase in illegal crossings is not clear.