The Port Isabel Lighthouse has long been a dominant feature at the southern tip of the Texas Gulf Coast. Its heavy brick walls have stood against the elements for more than a century, and for most of that time, its light has been a familiar aid to seafarers. 

The Region 

Spaniards discovered and mapped the Gulf shores, peopled by the coastal Borrado Indians, in the early 1500s. Some two centuries later, ranchers from Mexico settled in what became South Texas. By the 1830s, the small settlement of El Fronton de Santa Isabela became headquarters for one of the large ranches established by these settlers. 

In 1846, the United States military moved into the area under the leadership of Gen. Zachary Taylor when animosity between the U. S. and Mexico intensified. This brought South Texas national attention for the first time. Early battles in the Mexican-American War took place at Palo Alto and Resaca de la Palma, north of today’s Brownsville. Serving as a supply depot, Point Isabel received wounded soldiers from these conflicts. 

The point continued in use after the war to supply two military stations on the Rio Grande–Fort Brown and Ringgold Barracks. Because of the heavy shipping traffic through Brazos Santiago Pass to Point Isabel, a navigational light became a necessity. Land at the point was made available by the War Department, money was authorized by Congress, and construction of a lighthouse was underway by 1851. 

Two years later, the brick tower had been completed and was topped by a stationary white light that could be seen for almost 16 miles. The Civil War brought armed conflict once again to Point Isabel. Confederate forces held this area in the early stages of the war but gave way in 1863 to Federal troops who were sent to strengthen the blockade on Southern shipping. Both sides used the lighthouse as an observation post. At nearby Palmetto Ranch, Union and Rebel soldiers clashed on May 13, 1865, more than a month after General Robert E. Lee’s surrender at Appomattox. 

In 1866 the lighthouse was repaired and relit. For the next two decades, its beacon guided large numbers of commercial vessels to southernmost Texas. The light was extinguished between 1888 and 1894 during negotiations over ownership of the site; when finally reactivated, its years of service were numbered. The lighthouse was abandoned permanently in 1905 after shipping traffic declined. And although the coast was later active with defense measures during the two world wars, the tower at Point Isabel stood a dark watch. 

The lighthouse and its associated buildings were donated to the state in 1950 as a historic site by Mr. & Mrs. Lon C. Hill, Jr. and the Port Isabel Realty Company. The State Parks Board emodeled the tower by replacing the iron platform with concrete and by raising the glass dome to provide easier access for visitors. Additional repair work by the Parks and Wildlife Department was completed in 1970 and again in the 1990s when the Keeper’s Cottage was replicated to be used as a visitor center and museum. Of 16 lighthouses constructed along the Texas coast, Port Isabel Lighthouse is the only one now open to the public. 

Installation of a 3rd Order Fresnel Lens 

On November 16–17, 2022, a reproduction of the 3rd Order Fresnel Lens was installed in the Port Isabel Lighthouse. A celebration followed on December 9, 2022. The lens is on public display at the top of the Lighthouse. It is illuminated nightly to a soft glow and will be fixed (not rotating). Visitors are asked to refrain from touching it. Your respect of the lens will help preserve it for future visitors. 

Facts About the Lens 

  • Lens Assembly Weight and Height: 750 lbs., 5′ 3″ tall. 
  • Pedestal Assembly Weight and Height: 1,350 lbs., 8′ 1 3/4″ tall. 
  • Total Assembly Weight & Height: 2,100 lbs., 13′ 5 1/4″ tall. 
  • Lens Diameter: 3′ 6″. 
  • Lamp Assembly: 40 lbs. 
  • Original 3rd Order Fresnel Lens: Radius 19.7″; Height 5′ 2.05″; Weight 1,984 lbs.; Number built (384); Number in U.S. in 1900 (65). 
  • The Port Isabel Lighthouse does not operate as a navigational beacon and has not since 1905. 

At the full 1,000 wattage and while rotating, each bullseye causes a light beam to flash into the horizon. Historically, maritime traffic would have been notified by newspapers, so they would know to look for the light beam and its flash frequency. 

On April 19, 1853, this short announcement was published in the New York Herald, “Notice to Mariners. The lighthouse at Point Isabel and the beacon at the entrance to Brazos harbor, were lighted 20th ult., 1853.”