The city park in downtown Mountainburg has since 1980 hosted two large dinosaur models.

[5] Lake Fort Smith State Park, which is situated on the western side of the 1,400 acres (5.7 km2) Lake Fort Smith, is located 8 miles (13 km) north of Mountainburg.

[6] According to the United States Census Bureau, the city has a total area of 1.5 square miles (3.9 km2), all land.

[3] As of the 2020 United States census, there were 528 people, 252 households, and 136 families residing in the city.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.