34 
it has been silted up so that very slight depths (such as 3 fathoms) are 
encountered nearly midway across. The bottom is covered with fine silt 
containing some vegetable matter. In late winter and early spring the 
water is clear; during the rest of the year it is turbid, though never so foul 
as to be unfit to drink. The surface level has a maximum range of variation 
of about 7 feet. It is lowest in late winter and early spring, highest about 
midsummer, falls all summer, attaining a second minimum about the end 
of August, but rises to a second though inferior maximum in the autumn. 
The first minimum is due to the fact that at this time of the year precipi- 
tation takes the form of snow and so does not reach the lake; the first 
maximum is caused by the sudden melting of this snow in the early sum- 
mer. The second minimum is due to depletion of the supply of snow 
water and lack of rain at this season, and the second maximum is the result 
of autumn rains. 
The southernmost part of the district is traversed by the Canadian 
Pacific railway. A good road provides communication with Harrison 
Hotsprings at the south end of Harrison lake. Communication up and 
down the lake is effected entirely by boats. 
Very little was known of the geology of this district at the time the 
investigation was commenced. No areal mapping had been done except 
around Agassiz, where the geology was known only in a very general way. 
The first reference to the geology of the district was made in the Director’s 
Report,^ Geological Survey, Canada, in 1888. It stated simply that the 
older Cretaceous rocks were extensively developed in Harrison Lake dis- 
trict. In the following year proof of this statement appeared, in the 
announcement that Amos Bowman had in 1882 collected Aucella mosquensis 
var. concentrica Fischer from several localities on Harrison lake.^ In the 
sam*e year Dawson® listed the localities of the hot springs — St. Alice’ well at 
the south end of the lake, and St. Agnes’ well 5 miles beyond the north end. 
The following year Hoffmann^ gave analyses of the waters from the two 
springs, which compose St. Alice’ well. In 1895 Stanton® reported that the 
Ancellae from Harrison lake belonged to the species A. crassicollis Key- 
serling. 
Since these early contributions Harrison lake has scarcely been men- 
tioned in the literature. There is no information of any importance except 
Bowen’s reports on his reconnaissance of 1912 in which he barely touched 
the south end of Harrison lake, but provided a route map of the country 
about Agassiz.® Bow’en discerned a fossiliferous sedimentary series, of 
which he gives a section, underlying the country around Agassiz. In his 
“Columnar Sections”^ he called this the Agassiz series of Palaeozoic age, 
but in his summ.ary report® he used no name for it, but said it was of Lower 
Cretaceous or Jurassic age. He noticed that these rocks are intruded by a 
iSelwyn, A. R. C.: Geol. Surv., Canada, Ann. Kept., vol. Ill (1888). 
*Whiteave8, J. F.: Geol. Surv., Canada, Cont. to Can. Pal., vol. I, pt. 2 , No. 4 (1889). 
•Dawson, G. M.: “The Mineral Wealth of British Columbia"; Geol. Surv., Canada, Ann. Rept., vol. Ill (1889). 
‘Hoffmann, G. C.: "Chemical Contributio.ns to the Geology of Canada"; Geol. Surv., Canada, Ann. Rept., 
vol. IV (1890). 
•Stanton, T. W.: "The Fauna of the Knoxville Beds"; U.S. Geol. Surv., Bull. 133 (1895). 
•Routo-map between Lytton and Agassiz; Route-map between Agassiz and Vancouver; Geol. Surv., Canada, 
Guide Book No. 8, pt. II (1913). 
'Columnar Sections. N. L. Bowen, In the Coast Range. Camscll, C.: Geol. Surv., Canada, Guide Book 
No. 8, pt. II (1913). 
•Bowen, N. L.: "A Geological Reconnaissance of the Fraser River Valley from Lytton to Vancouver, Britiah 
Ckdumbia”; Geol. Surv., Canada, Bum. Rept. 1912 (1914). 
