The History of the Portage Lake Observatory
by Dave Snyder
Revised: March 2004
The Detroit Observatory became an unsuitable location due to the lights of
the growing city of Ann Arbor, its proximity to a dormitory for nurses, a hospital, a power plant and a railway
line (vibrations caused by passing trains sometimes made it difficult to perform accurate observations).
The need for a location away from city lights and the need for space to house other equipment prompted the University
to look for a location to house a new observatory. While other locations were briefly considered, an area
of land south of Base Line Lake and Portage Lake seemed to be a good candidate. (This is located about 15
miles northwest of Ann Arbor.)
Both the Astronomy Department and the Department of Forestry had an interest in this land (known as Peach Mountain).
Purchases in the area had already been made (first in 1925, when the Bell tract and another tract were purchased
for a total of 80 acres, and then in 1929 when the Newcomb tract was purchased). However the bulk of the
area was acquired by the State of Michigan in 1944 and transferred to the University in 1945. In addition
to the name Peach Mountain, the area also acquired the name “Stinchfield Woods” and was used by the Department
of Forestry for research. Two parcels within Stinchfield Woods were reserved for the Astronomy Department.
(These parcels are separated by approximately half a mile.) It was agreed that the Department of Forestry
and the Astronomy Department could use separate sections of the land (but the agreement was verbal, at least at
On the east parcel, a telescope and supporting residence were constructed. This observatory was referred
to by the name “Portage Lake Observatory.” After 16 years of use, the telescope was sent to Chile.
The observatory was abandoned and a new observatory was built along with a new telescope. Later the telescope
was moved to Kitt Peak and this observatory was also abandoned. The land reverted to the Department of Forestry
(ending the Portage Lake Observatory).
An chronology of events follows:
- 1924 - Land in the area was considered for a site of a new observatory.
- 1929 - 200 acres of land purchased near Portage Lake.
- 1930 - A 85.5” mirror was built and developed a fault. At this point, a 98.5” mirror was built.
The plan was to install this mirror in a new telescope, but this was delayed.
- 1945 - To simplify issues the Observatory Purchase, the Stinchfield Woods Purchase and the Newkirk Purchase
were made at the same time. There was a verbal understanding between the Department of Forestry and the Astronomy
- 1946 - The university decided it did not have the funds to use the 98.5” mirror. (This would have
required building a new telescope and a new building to house the telescope). The mirror was returned to
the McGregor Fund. No such observatory was ever built. The fund was founded by Tracy W. McGregor who had
an interest in astronomy. For a time Judge Hulbert was the secretary of the McGregor fund.
- 1947 - The University of Michigan starts a radio station (WUOM) and the broadcast tower is built on the northeast
corner of Stinchfield Woods.
- 1948 - Construction began on a new 36” Schmidt reflecting telescope. It was called the Curtis Telescope
after Heber Doust Curtis (see the McMath-Hulbert Observatory).
(The Curtis telescope can be seen in the upper left on photograph above;
Construction photographs of the Curtis Telescope.)
- 1950 - The Curtis Schmidt Telescope was finished. There were now two buildings on the site, one a residence
and the other a dome that houses the telescope.
(The residence can be seen in the bottom of the photograph above).
The telescope was devoted to the study of galactic and extragalactic
- 1952 - There were improvements: a new telescope drive, a program in photoelectric photometry was begun along
with direct and spectroscopic photography.
- 1955 - The western parcel began to be developed (see the Peach Mountain
- 1957 - AURA was formed (this was an organization comprising the Kitt Peak Observatory, the Cerro Tolol Interamerican
Observatory in Chile and the Sacramento Peak Observatory).
- 1957 - The McGregor Fund (already a contributor to the McMath-Hulbert
Observatory) also contributed to this observatory.
- 1967 - The Curtis Telescope was moved to the Cerro Tolol Interamerican Observatory. The University was
given the right to one-third of the observing days at the Cerro Tolol Interamerican Observatory (see Other
Observatories). In that same year the University of Michigan had some experiments aboard the NASA Orbiting
Solar Observatory III.
- 1969 - A new building was constructed that housed a new 1.3 meter reflecting telescope.
(This building can be seen in the lower right of the above photograph).
- 1969 - Due to dissatisfaction over the verbal agreement between the Department of Forestry and the Astronomy
Department, a written agreement was made.
- 1975 - AURA assisted in the movement of the 1.3 meter reflector to Kitt Peak where it became part of the McGraw-Hill
Observatory (see Other Observatories).
After the telescopes were removed, control of the parcel and the three buildings reverted back to the Department
There is no longer a Department of Forestry at the University of Michigan. Faculty members who were part
of the Department of Forestry are now members of the School of Natural Resources and Environment.
All three buildings still exist; in addition a classroom building was constructed.
(This building is in the middle of the photograph above).
Stinchfield woods was expanded somewhat since the original purchase including
land purchased in 1949 (to bring the total to 780 acres) and 90 acres of land acquired in two separate purchases,
the first in 1955-1956 and the second in 1964-1965. Neither purchase was used by the Astronomy Department.
The shore of Base Line Lake was never used by the Astronomy Department (as was the original intent), that area
is now the home of the University of Michigan Sailing Club.
Photograph taken by Mark Deseck, Summer 2001.
- Upper Left: The Curtis Schmidt Telescope.
- Lower Right: The 1.3 meter reflecting telescope.
- Center: The classroom building.
- Bottom: The residence.
A Olympus C-3030Z camera was used (1/100 second, f/2.8 at 19.1mm).
Copyright © 2015, the University Lowbrow Astronomers. (The University Lowbrow Astronomers are an amateur astronomy club based in Ann Arbor, Michigan).
This page revised Wednesday, January 28, 2015 9:43 AM.
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