tes, mixed, in thin layers, with compact, yellowish limestone, and
some pebbles of jasper interleaved with flinty slate.

The limestone ridge below the rapid stands on a narrow base, whose
transverse diameter does not exceed a quarter of a mile. Its summits are
generally conical, but very rugged and craggy; the highest peak I had an
opportunity of visiting is about a mile from Bear Lake River, and it has
been already stated to be estimated at eight hundred feet above that
stream, or nine hundred and fifty above the sea. The general direction
of the ridge is from S.E. by S. to N.W. by N., or nearly parallel to the
great Rocky Mountain chain, and to the smaller ridges betwixt it and
that chain. Its prolongation through the flat surrounding strata, to the
southward of Bear Lake River, can be traced for at least forty miles,
and it is visible at nearly an equal distance, as it runs through the
still more level country to the northward; but here, as has been already
said, it appears to incline towards the similar ridge which is cut by
the Mackenzie, at the mouth of the Bear Lake River, and is about
twenty-five miles to the W.S.W., in a direct line. That part of the
ridge which I had an opportunity of visiting, consisted entirely of
limestone, generally in thick beds. Its stratification was not very
evident, and in my very cursory examination the general dip was not
clearly ascertained. A precipitous cliff, four hundred feet high, facing
the S.E., and washed by the Bear Lake River, presents strata, inclined
to the S.W. at an angle of 45 degrees, which may be perhaps considered
as the general dip; for the ridge on that side slopes down to the
surrounding country at an angle of about 30 degrees or 40 degrees, while
on the N.E. side it presents lofty precipices formed by the cropping out
of the strata. [Sidenote: 39, 34] Many of the beds in this hill
consisted of a blackish-gray fine grained limestone, intersected by
veins of calc-spar; [Sidenotes: 40; 35, 36; 42, 43, 44] but several
layers of gray and dark coloured dolomites, and some of a yellowish-gray
_rauchwacke_, were interstratified with them, and the upper parts of the
precipitous cliff, [Sidenote: 35, 36] and also of the highest peak,
consisted of a calcareous breccia, containing rounded pieces of brown
limestone, and angular fragments of chert; and the faces of some
cliffs, on the N.E. side of the hill, were incrusted with a fine
crystalline gypsum to the depth of from