[3]: 4  The map included here shows the main watershed regions for the Adirondack Mountains with the star marking Twitchell Lake in Big Moose, NY, where Frank Tweedy had a surveying basecamp for his 1879 season.

The thickness of the wilderness, and resulting poor visibility of established towers and stations, forced crews in the western Adirondacks to rely heavily on ground surveys.

4-- one of five Colvin instructed Tweedy to install along that 24-mile T&C western boundary line—was discovered "in the solid rock" directly under that cairn of stones marking an important historical Corner.

This excursion, not far north of the route taken by Lewis and Clark, became the centerpiece in Frank Tweedy's autobiography, where he narrated seven dangers faced that tested his faith and shaped his character.

"[27] Tweedy's survey work at this time added to a new effort by USGS to create and publish a Geologic Atlas of the United States," with Frank's topographical contribution on the "Three Forks, Montana Folio which was part of this publication.

[28] With few visible peaks in his earlier Adirondack survey work, Tweedy was unable to lay out many right triangles with a baseline for calculating multiple distances from that base via Pythagorean geometry.

"[29]: 295  The National Geologic Map Database project (NGMDB) lists the following Quadrangles for which Frank Tweedy headed up both triangulation and topography: In Montana, Helena & Fort Logan (1888) and Big Timber (1889); and for Wyoming, Ishawooa (1893), Laramie (1895), Bald Mtn (1898), Dayton (1899), and South Dakota-Newcastle (1899).

[32] The NGMDB displays the following sampling of six Quadrangles from this period for two states: In South Dakota, Red Water (1903–1906); and in Colorado, Central City (1904), Fort Collins (1905–1906), Loveland (1905–1906), Livermore (1905–1907), and Eaton (1908).

[30] By the completion of his career, Frank Tweedy contributed significantly to the triangulation and topography for over 20 USGS Quadrangles in five Rocky Mountain States, overseeing the mapping effort in those surveyed after 1900.

His first affiliation was the Cosmos Club, formed in 1878 by men who "performed meritorious original work in science, literature, or the fine arts," with topographers such as Frank admitted because they authored maps which they had executed in the field.

Afterwards, there were toasts, original poems, oratory, and tales of glaciers, torrents, swamps, deserts, and forests encountered and conquered during the past field season in the remotest parts of the United States.

Frank Tweedy's 43 years of service with the USGS positioned him as a founding member of several societies which helped to shape our understanding of geography, geology, topography, and mapping.

The ninth president of Union College, Andrew Van Vranken Raymond, said this at the 50th anniversary alumnus event Frank missed due to health problems: "Tweedy has been connected, almost from the time of graduation, with the U. S. Geological Survey spending his summers in the western wilds and his winters in the offices at Washington.

In 1882, Tweedy's botanical explorations jumped across the continent when he took a job as assistant topographer for the Northern Transcontinental Survey in Washington Territory (he continued to live in Newport during the winter).

[10] Tweedy routinely sent his more challenging specimens to experts at academic institutions for determination, verification, or description and publication if novel, as was common practice for field botanists at the time.

[10] He was greatly impressed by its geographical diversity: "There is probably not an area of equal size in the United States which has as varied topographical features as the region of the Yellowstone Park, with elevated plateaux and lofty mountain ranges, cañons, rivers and cataracts.

Tweedy mentioned the "treacherous hot spring bogs throughout the park" with their "peculiar flora", and in a rare digression from botany, noted that his time in Yellowstone wasn't always pleasant.

"Aside from the wonderful geyser basins and hundreds of boiling springs, but few regions can compare with it in the variety of its topographic features : — Plateaus diversified by deep cañons, lakes, and ponds of the greatest beauty of outline; mountain ranges of every possible description, from the rounded massive form to those of the most rugged and precipitous character."

He then described at length, five pages in all, the geographic regions, topographical features, streams and lakes of the Park, the intent being to provide a reference source for locations mentioned later in the book.

[44] In his description of Park vegetation, Tweedy addressed Forests; Alpine Flora; Bogs, Ponds and Streams; Hot Springs and Geyser Areas; and Grasses.

Pushed southward by the extreme cold, and then, as the climate moderated, retreating northward, following the receding glaciers, they were left stranded on the mountain summits, and finding a congenial home, have there persisted.

Most puzzling was the mix of biogeographic affinities: "The alkaline nature of the soil and artificial warmth of the hot spring and geyser areas have created a flora in many respects peculiar to itself.

Near the end of his description, Tweedy hinted that plants offered him more than just Latin names: "The latter [a short panic grass] frequently covers the ground with a dense velvet carpet, glistening with crystal drops of condensed steam.

[45][46] In 1898, when Professor Aven Nelson of the University of Wyoming was planning a lengthy plant collecting trip to Yellowstone, he contacted Rocky Mountain botany expert Per Axel Rydberg for advice.

His findings, including a description of the mountain range, were published by Joseph Nelson Rose, who noted: "No attempt was made by Mr. Tweedy to get a complete representation of the flora of this region, which is extremely rich and varied.

[3] These works penned later in his life reveal Frank's faith and reflection on his vocation and purpose, his thirteen Adirondack Field Books held by the New York State Archives being "all business.

He offered the following "confession" at age 64: In my more than three decades of wanderings along the backbone of the continent and on its slopes, in the cow country, rough mining regions, and lumber camps I lost nothing of health or morals...What I was doing in 1892 I have been doing ever since and am doing now, looking out upon the world with eyes of faith.

"[3]: 70 After Lewis and Clark, Tweedy found inspiration from English poets, a handful quoted as he reflected on this two-week ordeal in his autobiography—including Tennyson, Longfellow, Milton, Coleridge, Landor, and Kipling.

[3] Rudyard Kipling's poem "The Explorer" later look on added meaning for Tweedy as he recalled the seven dangers he survived during that exploratory trip to Montana and Washington:[3]: 32  [62]: 19–22 Something hidden.

"[3]: 71 [60] passion for the wildness and beauty of nature—his window being the world of plants, his pioneering spirit for exploration and discovery, and his adherence to a faith and ethical standard that earned the respect of his peers, these three things and more went into shaping Frank's legacy.