854 The American Geoloijisi. May, 1897 
precipitous canyon-walls, while the remaining upper portion (the Dog 
Creek dolomites) forms the less steeply cut walls and uneven floor of a 
broad, basin-shaped infra-sylvan excavation, or amphitheatre, which I 
shall call the Chapman amphitheatre, after Mr. H. C. Chapman. It is 
the same as the "Natural Bridge park." cited by the writer in a previ- 
ous article, from Mr. Chapman's letter. Descending from the sandy, 
wooded rim, the incij)ient drainage lines of the amphitheatre converge 
to a canyon dovvn which descends steeply, from the base of the Cave 
Creek formation to a level some 160 feet lower, a dry torrent bed, strewn 
with blocky boulders of gypsum. At the foot of this lies a moderately 
inclined, narrow, springy mud-flat, or salt-plain, the head of which is 
that of permanent flow in Salt creek, and practically marks the summit 
of the Salt Plain measures. This salt-flat varies from 20 to 50 rods in 
width, and has a length of between three and four miles. Its upper end 
is ensconced in the depths of the canyon, the lower part being in the 
more open country where the great Trans-Oklahoman or Mareij* bluff- 
range breaks down to the peneplain of the Cimarron river. From this 
flat arises and through it flows the brine-stream, which, beginning as a 
mere rill at the upper end of the incline, and joined in its course by oth- 
er rills and rill-formed branches, soon attains the proportions of a large 
brook. The latter maintains its character as a pure brine-stream till it 
reaches the mouth of Bitter creek, by whitfh it is rendered too impure 
for use in salt-making, as the water brought into it by Bitter creek is 
highly charged with gypsum. 
At the time of my visit to this locality, to which I was conducted by 
the kindness of Mr. H. C. Chapman, salt was being manufactured by 
five different parties who had taken up claims along the borders of the 
brine-stream. This salt is manufactured very cheaply, as the brine, 
according to members of the White family, who were the largest manu- 
facturers, is so strong that it makes from one-third to one-half of its 
bulk of salt, and fuel is cheaply obtained from the Black-jack woods 
that clothe the Jack-sands on the neighboring hights, a little cedar also 
(now nearly exhausted) being cut and rolled down the bluff for fuel at 
the Saunders salt works, which are in the deepest part of the canyon 
and nearest the head of the stream. The salt was being hauled by 
by wagon to Kingfisher and El Reno and sold there, it was said, at a 
price so low as to compel a reduction in the former price of the Kansas 
salt sold in those markets.! 
Owing to the crudeness of the method of manufacture now employed 
at Salt creek, the salt there produced contains a trace of red clay sedi- 
ment, or of ferric oxide derived therefrom, imparting to it a faint red- 
dish tinge. This, however, could be easily overcome, and there is no 
reason why the finest grades should not be made there. With the brine 
strong and pure, no pumping necessary, and fuel cheap and abundant, 
the natural conditions for the cheap manufacture of salt are there ap- 
*After C'aptain R. B. Marcy, who (? first) more or less discrimiaatiugly studied it, 
and called attention to it by description and mapping in his Red Eiver report. 
tVVholesale at $6 per ton ; retailed at 50 cents per sack of 100 pounds. 
