Crater of Diamonds State Park is a state park in Randolph County, Arkansas. The park includes the 755-acre (3.19km2) Crater Lake and an extension to its south that makes it 1,140 acres (4.69km2). Its main feature, Crater Lake, is a bowl-shaped depression with steep sides up to 60 feet (18m) high. It has an average depth of 30 feet (9.1m), but reaches a maximum depth of 65 feet (20m). The lake provides a habitat for crappie, catfish, bass, and sunfish. A fishing center near the dam offers boat rentals, camping facilities, picnic areas, playgrounds, and interpretive programs. There are also hiking trails at the park.
Crater of Diamonds was formed by volcanic activity around 2 million years ago as a result of seismic activity following the formation of the Appalachian Mountains. This area of the Ozark Plateau experienced intense heat and pressure during creation of the mountain chain, causing the igneous rock to fracture along vertical joints or faults.
When the pressures were released, huge volumes of gas escaped from the fracturing stone, forming craters. One such crater, which later filled with water, became Crater of Diamonds. Another similar crater nearby, named Cane Creek Crater, still contains steam rising from underground. Seismic activity again focused the attention of geologists on this part of the Ozarks about ten years after oil was discovered in the region.
Crater of Diamonds State Park features two swimming areas, rental paddleboats, campsites for family, group, equestrian, and primitive trail camping, cabins, hiking trails, playgrounds, picnicking facilities, and a general store. Fishing opportunities exist year round, with a special fishing center available March through October. Lake Poinsett freezes solid every winter, so ice fishing takes place year round. Crappies, bluegill, catfish, and bass are common fish caught. Campsites range from modern with running water and electricity, to more rustic tent sites without conveniences. Backcountry camping is allowed in designated areas.
Two backpacking shelters built by the Civilian Conservation Corps (CCC) are featured in the southern half of the park. They can each accommodate six people in three separate dormitory style bunk beds, have electric lights and outlets, and include cooking grills and tables. Picnic tables and charcoal grills are located nearby. Rental paddle boats are available at both docks throughout the year. Canoes, kayaks, and pedalos are available to rent when the weather permits. Hiking trails wind through forest and marshland, ranging from less than one mile to 3+ miles in length. Mountain biking is permitted on certain trails.
The park’s marina accommodates campers, hikers, paddlers, and other travelers. Boat slips are available at both docks. Ramps are located on Highway246 providing access to the lake for vehicles. The park hosts many events including festivals, parades, and fairs.
Ramps are closed until further notice. The South Marina remains open 24/7. Boats may be launched into the lake any time, however swimming and beachcombing are not recommended due to dangerous conditions. Winterization procedures are strictly enforced. No alcohol, glass, kites, drones, fireworks, hunting, or explosives are permitted on the property. Parking fees are in effect all year long. The annual Crater of Diamonds Kite Festival is held at the park. Entrance fees are waived for those attending the event.
Geologist Fred Fisher conducted research here in the 1930s, and found evidence that some of the fractures had been filled by lava flows. Similar evidence was obtained by Jack Horner who worked on the site in the 1950s; he showed that the “basalt” covering the crater contained tiny crystals of quartz that grew over older, darker rocks. In 1957, Horner reported finding what appeared to be fossilized tree trunks buried in the basalt. These discoveries led to increased interest in Crater of Diamonds, and in 1960, the U.S. Army Corps of Engineers began construction on a dam across Cane Creek. At first, local opposition to the project existed, but support among residents and politicians eventually materialized. The resulting reservoir, Lake Poinsett, provided irrigation for farms and drinking water for homes in central Arkansas. However, the dam did not provide all the expected benefits, and soon became notorious for frequent flooding. After several failed attempts, a new dam was completed in 1969, allowing for recreational use of the lake. The state park opened to the public in 1974.
Other activities at the park include:
- horseback riding
- disc golf
- bumper boat rides
Activities available at the park change seasonally, depending upon availability of personnel and funding. For example, during the summer of 2020, only limited services will be available at the North Marina.