Crigler Mound Group
The Crigler Mound Group is an important archaeological site in the northeastern part of the U.S. state of Missouri. Located in the Salt River valley near Mark Twain Lake, these burial mounds have been named a historic site. In the 1960s, the Crigler mounds were seemingly the largest and best-preserved group within what was soon projected to become the Joanna Reservoir. The site occupies a high hilltop approximately north of the original Salt River bed. Composed of seven large mounds, the entire group covers an area nearly long, in and around the Crigler Cemetery north of  the village of Florida; six are made solely of earth, while one includes substantial rocky components. The mounds are in a straight line with an orientation of 320°, or approximately northwest. The mound on the southern end of the group, designated No. 1, is a circle in diameter and high, with a slight depression in the center. Mound No. 2 is a flat-topped circle measuring by . A depression similar to the one in No. 1 is found atop Mound No. 3, a circle measuring by and the only mound composed partly of rock; surveyors in the 1960s deemed  the depression evidence that there had formerly been a structure within the mound that had collapsed. No. 4 is long by wide and high; it has been damaged by rodents burrowing into its side. Mound No. 5 is in diameter and high. The top and center portion is almost flat and slightly depressed. Mound No. 6 is in diameter and high, and it too is flat-topped with a slightly sunken center. Mound No. 7 was approximately 32 feet in diameter and 2 feet high, but the construction of a roadway necessitated the grading of most of the mound; only  about 25% of the original mound survives. No bones or artifacts were found when the grading was performed, and no other excavations have been conducted in living memory, if ever. On May 21, 1969, the Crigler Mound Group was listed on the National Register of Historic Places because of its archaeological value. The site was one of the first two Monroe County sites listed on the Register, along with the Mark Twain Birthplace State Historic Site in Florida, which gained the designation on the same day.