up to 100 men separated by difficult terrain with only primitive communication methods. He also designed and built some tools for the job, including a folding canvas boat, and a wind powered spinning reflector to enable precise sighting of a mountain top from many miles away. During the first year the surveyors discovered Lake Tear-of-the-Clouds, often considered the source of the Hudson River. Colvin directed surveying parties throughout the Adirondacks and determined the altitudes of most of the highest peaks, becoming obsessed with his task. Determined to fix the precise altitude of Mount Marcy (having decided that the barometric method of determining altitude was insufficiently accurate) he established a series of 111 elevation benchmarks along the course of a forty mile trek from Westport on Lake Champlain to the summit of Marcy, each intermediate altitude being calculated to a precision of one-thousandth of a foot. As the crew approached the summit of Marcy, they encountered an October snow storm with ice and freezing rain; despite urging by his guides and assistants to wait for better weather, Colvin pushed on despite the danger of becoming trapped in Panther Gorge. At 4:50 PM on November 4, 1875, he took the final observation on the summit of Mt. Marcy and determined its elevation to be 5,344.311 feet above mean tide level in the Hudson. Upon his return to Panther Gorge later that evening, Colvin wrote "Joy reigned in the camp to-night, for we had accomplished the work in the face of the greatest difficulties; when the most experienced guide had ventured to say that it was for this season impossible. In honor of the event we had a choice supper of bear's meat fried, boiled and stewed, and hard bread and biscuit; then, unmindful of the snow storm beating in and around our open shanty, fell fast asleep." In 1873 Colvin wrote a report arguing that if the Adirondack watershed was allowed to deteriorate, it would threaten the viability of the Erie Canal, which was then vital to New York's economy, and that the entire Adirondack region should therefore be protected by the creation of a state forest preserve. He was subsequently appointed superintendent of the New York state land survey, which led to the creation of the Adirondack Forest Preserve in 1885. His work ended in 1900 when then Governor Theodore Roosevelt transferred his duties to the state engineer. Mount Colvin in