Old Growth Island, Oklahoma
Research Natural Area

Old Growth Island is located in Lake Eufaula, Oklahoma, just east of Arrowhead State Park. Old growth forest and glade grasslands cover most of the island. The island is never connected by land to the mainland, but we have seen coyotes and deer sign on the island. The island is entirely on federal land in Section 14 (T8N R16E) and covers approximately 70 acres. The steep sided, flattop island rises to an elevation of 675′, and was created by the impoundment of Lake Eufaula in 1964. Most of the island lies in the southwest 1/4 of Section 14, and old fence lines are evident on the north and east margin of this quarter section. These fence lines appear to mark very different land uses prior to the development of Lake Eufaula. Old growth woodland, savanna, and undisturbed glade grasslands are present inside of the fence line in the southwest 1/4 of Section 14, and cover approximately 50 acres. The area north and east of the old fence lines was cut over and is now wooded with second growth. The lakeshore of the island has been impacted by high water and erosion, but the slopes and ridge top are in excellent condition and include centuries-old postoak (Quercus stellata), ancient American ash (Fraxinus americana), interesting rock formations, and excellent glades with native grassland species. There are no old-growth red cedar on the island, but many young red cedar have grown up in some of the old-growth forest and grassland.

The Ancient Cross Timbers Consortium has been granted a long-term administrative lease to Old Growth Island by the U.S. Army Corps of Engineers, for the purpose of non-destructive ecological and paleoclimate research. We believe that the encroachment of young red cedar presents a research and management challenge for the old growth forests and glades on the island. We will soon fly a Terra Hawk sensor over the island, which may be capable of mapping the exact location of every shrub-size (or larger) red cedar on the island. We then plan a series experiments designed to remove and control invasive red cedar.