Estero Llano Grande State Park of Mercedes is known for its great birding, nature trials and habitat restoration in becoming one of the more popular go-to places for wildlife enthusiasts in the Rio Grande Valley.

After walking into the main entrance of Estero Llano, there are snapshots of history to go with the splendors of nature. A series of enlarged photos with narratives by them tell the story of Camp Llano Grande, which was one of a line of military encampments established in the Valley in the early 1900s to deal with raids and turmoil spilling over from Mexico during its revolutionary war era.

Camp Llano was located near the recently established community of Mercedes and to the east of present day Estero Llano Park. The military camp near Mercedes was occupied from 1916-17 with National Guard troops from Indiana, Minnesota and North Dakota. They were called to duty by President Woodrow Wilson under the National Defense Act, which was triggered by cross-border raids led by Mexican revolutionary Francisco “Pancho’’ Villa into New Mexico.

The 13,000 National Guard troops from the Midwest called to duty at Camp Llano were to patrol the Rio Grande and defend South Texas from similar attacks coming from Mexico. Those troops found a region just recently settled and in its infancy of the decades of development to follow.

“Last night, just west of here, a rattlesnake measuring seven feet, two inches, was killed, and tarantulas are as common as spiders,’’ said Mrs. Edmund Remington, as identified in mnmilitarymuseum.org, and as a state secretary of the Minnesota YMCA, was at Camp Llano to establish recreational facilities. “It’s all part of life here.’’

Remington also found an active military outpost in the South Texas wilderness.

“I think I never saw a busier place,’’ she wrote. “Bugle at 5:30 a.m. Taps at 10 p.m. “Baseball games (and the) boys raised money for a piano and it is going all day and night.’’

Camp Llano covered 200 acres and included a headquarters building, a commissary, and buildings for medical and recreational services. It was a fairly uneventful two years for the National Guard troops in Mercedes. Military historical publications report that the presence of a large military force on the border served as a deterrent to raids and disturbances. The only recorded incident occurred on Aug. 30, 1916.

“A detachment from the First Minnesota was guarding the Mercedes pumping station on the banks of the Rio Grande when they were fired upon from the Mexican side,’’ said a report of that account published by mnmilitarymuseum.org. “This prompted an exchange of 150 rounds. No Minnesotans were hit; Mexican causalities were unknown.’’

The camp closed in March 1917 when a much bigger challenge called – World War I. The troops from the Midwest stationed in South Texas quickly shipped out for war service in France.

It was a brief but memorable time in Valley history and one worth remembering.

“It is important to mention the history of the local area so park visitors can get a complete picture of the site, including any historical aspects of the park in addition to the natural beauty of the park,’’ said Javier de Leon, the park superintendent at Estero Llano Grande. “If visitors ask where the (park) name came from, we can tell them that this area was once covered in grasslands – llano – and was large – grande.’’

As was Camp Llano, at a site near today’s Business 83 that has now slipped into being a historical account with pictures to prove it once existed.

• Ricardo D. Cavazos