Question: The Green Mountain Cog Railway was a mountain railway built to carry tourists to the top of a mountain that is how tall?

Context paragraphs:
Green Mountain Reservoir: Green Mountain Reservoir lies at the northern end of Summit County, Colorado along the Blue River.  The Green Mountain Dam was built between 1938 and 1942 by the United States Bureau of Reclamation.  The reservoir and its dam store water to benefit Colorado's Western Slope.  Created by President Roosevelt as part of the Colorado-Big Thompson Project in 1937, Green Mountain was the first facility to be constructed.  This is because it represents a great compromise that made the C-BT project possible: it compensates the Western Slope for water diverted to cities in Northern Colorado from Granby Reservoir further upstream on the Colorado River.  Water from Green Mountain Dam is released either over the spillway, through the dam, or through the hydroelectric powerplant at the dam's base.  The Green Mountain Power Plant has the capacity to generate up to 21,000 kilowatts, using two generators.  Combined with the other five Federal power plants on the C-BT, enough electricity is produced annually to power almost 60,000 American homes.

Quincy and Torch Lake Cog Railway: The Quincy and Torch Lake Cog Railway is a half-mile long, cog railway in Hancock, Michigan.  It opened in May 1997 to transport tourists to the adit entrance of the Quincy Mine's Number 5 shaft.  Its tram car has a capacity of 28 people and travels at a maximum grade of 35%.  It is one of only a few rack railways in the United States.

Mount Washington Cog Railway: The Mount Washington Cog Railway is the world's first mountain-climbing cog railway (rack-and-pinion railway).  The railway is still in operation, climbing Mount Washington in New Hampshire, USA.  It uses a Marsh rack system and one or two steam locomotives and six biodiesel powered locomotives to carry tourists to the top of the mountain.  Its track is built to gauge, which is technically a narrow gauge, as it is a ⁄ -inch (12.7 mm) less than .

Rack railway: A rack railway (also rack-and-pinion railway, cog railway, or cogwheel railway) is a steep grade railway with a toothed rack rail, usually between the running rails.  The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail.  This allows the trains to operate on steep grades above around 7 to 10%, which is the maximum for friction-based rail.  Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment.

Eibsee Cable Car: The Eibsee Cable Car, which opened in 1963, is a cable car which connects the lower station (973 m above sea level) near lake Eibsee with the top station at 2950 m above sea level next to the summit of Zugspitze, Germany's highest mountain on the border to Austria.  The cable car was built to provide a faster access to the Zugspitze from its German side, as the cog railway from Garmisch-Partenkirchen does not go directly to the summit and takes much longer.  The "Eibsee Cable Car" belongs to "Bayerische Zugspitzbahn Bergbahn AG", the company operating the cog railway and most cable cars, gondola lifts and chairlifts in the Garmisch-Partenkirchen area.  It is thus possible to make round trips using both the cog railway and the cable car.  On the Austrian side, there is the Tyrolean Zugspitze Cable Car which starts at Ehrwald and meets the Eibsee Cable Car on the top.

Cadillac Mountain: Cadillac Mountain is located on Mount Desert Island, within Acadia National Park.  With an elevation of 1,530 feet (466 meters), its summit is the highest point in Hancock County and the highest within 25 mi of the shoreline of the North American continent between the Cape Breton Highlands, Nova Scotia and Mexican peaks 180 mi south of the Texas border.

Green Mountain Cog Railway: The Green Mountain Cog Railway was a mountain railway built to carry tourists to the top of Green Mountain (now known as Cadillac Mountain) on Mount Desert Island in Maine.  Its track was built to gauge, which is technically a narrow gauge, as it is a ⁄ -inch less than .

Most–Moldava railway: The Most–Moldava railway is a branch line in Czech Republic, which was originally built and operated by the Prague-Dux Railway.  The line, formerly known as the"Teplitz Semmering Railway" ("Teplitzer Semmeringbahn") runs from Most ("Brüx") over the Ore Mountains to Moldava ("Moldau") and used to have a junction with the Nossen-Moldau railway there in Saxony until 1945.  In the Czech Republic the line is known today as the "Moldavská horská dráha" ("Moldau Mountain Railway") or "Krušnohorská železnice" ("Ore Mountain Railway").

Manitou and Pike's Peak Railway: The Broadmoor Pikes Peak Cog Railway (also known as the Pikes Peak Cog Railway) is an Abt rack system cog railway with track in Colorado, USA, climbing the well-known mountain Pikes Peak.  The base station is in Manitou Springs, Colorado near Colorado Springs.

Alamogordo and Sacramento Mountain Railway: The Alamogordo and Sacramento Mountain Railway was built as a branch line for the El Paso and Northeastern Railway (EP&NE).  Construction began from the EP&NE connection at Alamogordo, New Mexico, in 1898 to reach the Sacramento Mountain fir and spruce forests to the east.  Sawmills were built in Alamogordo to mill lumber for extension of the EP&NE to reach the Chicago, Rock Island and Pacific Railroad.  The railroad reached Cloudcroft, New Mexico, in 1900, where a lodge was built for summer tourists to enjoy the cool mountain air.  Cloudcroft was laid out in several villages so tourists might avoid associating too closely with loggers and railway workers.  The railway was extended from Cloudcroft to the small community of Russia, New Mexico, in 1903; and several branches were built to reach timber for the Alamogordo Lumber Company.

Supporting paragraphs: Green Mountain Cog Railway Cadillac Mountain
Answer: 1,530 feet