Not as high, and lesser known than the more famous Niagara Escarpment, the Onondaga Escarpment is Western New York's "other escarpment".
Varying in height from 10 ft. to 245 ft., the Onondaga Escarpment runs roughly from Pt. Colborne Ontario, to near Albany, N.Y.
An escarpment is a steep slope or long cliff that results from erosion or faulting, and separates two relatively level areas of differing elevations. The exposed surface of the Onondaga escarpment is limestone, a common sedimentary rock consisting mostly of calcium carbonate, used as a building stone and in the manufacture of lime, carbon dioxide, and cement.
In New York State, the Onondaga Escarpment basically parallels Rt. 5. Some of the higher points in the City of Buffalo include City Honors High School (at the corner of Masten and Best) and near the intersection of Bailey and Kensington.
The escarpment is at it's highest points in Erie County through Clarence and Newstead. You can visit the Clarence Escarpment Sanctuary, or the Onondaga Escarpment State Unique Area (Newstead), both of which have geocaches. The escarpment also offers a nice view of Transit Road, looking Northward towards Lockport from Sheridan Drive, near the Eastern Hills Mall.
In the Village of Williamsville, within the Town of Amherst, Ellicott Creek tumbles over the escarpment at a 30 ft. two-stepped waterfall known as Glen Falls, which is what you will be visiting as part of this EarthCache. Other notable local Onondaga waterfalls include Serenity Falls (Buffalo, Scajaquada Creek), Akron Falls (Akron, Murder Creek), and Indian Falls (Pembroke, Tonawanda Creek).
Forty seven mile long Ellicott Creek has it's source in the Town of Bennington in Wyoming County, and empties into Tonawanda Creek, less than a mile from the latters confluence with the Niagara River. Ellicott Creek is considered a tributary of Tonawanda Creek.
Park at N 42 Deg. 57.938' W078 Deg. 44.675'. There is a lot closer to the falls, but all spots are designated handicap parking (this EarthCache is 100% handicap accessable). Original logging requirement, no longer mandatory: Go to the coordinates at the top of this page, and upload a photo of someone in your caching party holding a GPSr with Glen Falls in the background (or your hand holding a GPSr if you are by your lonesome).
An additional logging requirement for logging Earthcaches was added in late 2006, you must perform a "task". Your task is to estimate the width, in feet, of Glen Falls. This would be known as it's "crest" in waterfall terminology 
. A good method of doing this would be if you were say 6 feet tall, guess how many times you'd have to lay your body across the top of the falls. Don't do it, it's illegal . Email me this answer through the emai link in my profile. This is a mandatory requirement.
Logs without an associated email may be deleted.
By the way, this was the first Earthcache in the State of New York. It was once on an "oldest Earthcaches" bookmark list, but it was either deleted, or the owner let their Premium membership lapse. Earthcaches claim a 2004 birthdate, but only "Earthcache insiders" could create them, and they only became available for the general Geocaching public to create in February, 2005.