INDIAN LADDER SECTION 



Near the northern end of the Helderberg mountains, about south 

 of Meadowdale, on the Susquehanna division of the Delaware and 

 Hudson railroad, is the highway known as the Indian Ladder 

 road and the only one climbing these precipitous cliffs between 

 New Salem and Altamont. The Tentaculite and Pentamerus 

 limestones form the prominent cliff which extends from New 

 Salem around the northern end of the mountains to Altamont; 

 but on the higher terraces and hills to the south the later forma- 

 tions are found, and their distribution is shown on the " Prelimi- 

 nary geologic map of Albany county, New York," by N. H. Dar- 

 ton. 1 Along the Indian Ladder road are exposures of the upper 

 part of the Hudson f ormation, with magnificent cliffs of the Tenta- 

 culite and Pentamerus limestones; while to the east of south the 

 succeeding hills show the later formations up to the lower part 

 of the Hamilton, which forms the upper part of Signal station 

 hill. 2 The section from Meadowdale to the top of Signal station 

 hill is as follows : 



Feet 



V A 1 Covered from the station to a point near the base 310=310 

 of the steep part of the hill on the Indian Ladder 

 road. 

 A 2 Partly covered; shales and thin sandstones of the 400=710 

 Hudson river beds exposed along the road. At the 

 top a massive sandstone 30 or more feet in thick- 

 ness shown at the base of the cliff to the east of 

 the road, which may be called the Indian Ladder 

 cliff, at the waterfall. Mr Walcott reported "about 

 300 feet of the Hudson " in this section, and 

 found specimens ofOrthis testudinaria 

 and Trinucleus concentricus. 3 



H5th ann. rep't N. Y. state geologist. 1895. 



2The station was called Helderberg, and is 1823 feet A. T. — Final results 

 of the triangulation of the New York state survey. 1887. p. iii 

 3Bul. geol. soc. Amer. 1890. 1:345. 



