two Small fortifications is on the Arc Creek on the upper side 1st 1/4 of a mile up & the 2d 1/4 higher, nearly Square each angle 100 yards
[Clark, September 2, 1804] 2nd September Sunday 1804 Set out early and proceeded on Passed the Island and Landed on the S. S above under a yellow Clay bluff of 110 feet high, the wind blew verry hard a head from the N. W. with Some rain and verry Cold, G. Drewnyer R. Fields Newman & howard Killed four fine Elk we had the meat all jurked and the Skins Dried to Cover the Perogue, on the Side of the Bluff I observed Bear Grass & Rhue, at Sun Set the wind luled and Cleared up Cold, the high land on the L. S. is verry high, & uneaven, that on the S. S from 80 to 120 foot & is leavel back but fiew Small Streems falling into the river.
I went out and made a Survey of the antient works which is Situated in a level plain about 3 miles from the hills which are high.
(1) Commenceing on the river opsid the Good Mans Island, first Course from the river is
S. 84 W. 53 yards (at this angle a kind of angle or horn work)
N. 69 W. 300 yards to a high part, passing the gateway Covered by two half Circler works one back of the other lower than the main work the gate forms a right angle projecting inward
N 20 W. 73 yards This part of the work appears to have either double, or a covered way. from this Some irregular works appear to have been on mounds between this and the river with a Deep round whole in the center of a gorge formed by another angle ------ (578)
This part of the work is from 10 to 15 feet 8 Inches--the mounds of various hights--the base of the work is from 75 to 105 feet, steep inward and forming a kind of Glassee out wards
N. 32°W. 96 yards to the Commencement of a wall from 8 to 10 feet high this corse not on the wall but thro to the commencment of another detached
N. 81° W 1830 yards to the river & above where this bank Strikes the river is the remains of a Circular work
in this Course at 533 yards a Deep Pond of 73 yards Diameter perfectly round is in the Course of the bank which is about 8 feet high, from this Pond the bank it lowers gradually--a bank about the Same hight runs near the river, and must have joined the main work at a part which is now washed into the river, this is also perfectly Streight and widens from the main work, as the river above has washed in its banks for A great distance I cannot form an Idear How those two long works joined--where they Strike the river above, they are about 1100 yds apart, I am informed by our freench interpeters that a great number of those antint works are in Different parts of this Countrey, on the Platt River, Kansus, Jacque, Osarge Mine river &c.