Guidelines for a Pleasant Visit-Information Release-History

Information Release ( *updated 7/19/2014 )

SITE: Boyce Thompson Arboretum is 55 miles east of Phoenix, in the Arizona Upland division of the Sonoran Desert. It is located near U.S. Highway 60 milepost #223 on the south side of the road, just west of Superior, in Pinal County. GPS Coordinates N 33.28094*,W 111.16135* US-AZ mapcode MC3.WC4
The Arboretum lies along Queen Creek, an intermittent desert stream which flows through a picturesque canyon. The Arboretum is nestled against the base of the 4400-foot-high Picketpost Mountain. Elevation in the gardens is 2,400 feet, latitude 33 16' 24" N, longitude 111 90' 24"W.

PURPOSE: The Arboretum was created from 1923 to 1929 as a museum of living plants to help instill in humanity an appreciation of plants. The articles of incorporation allow for all forms of "experiment, research, study and investigation of plant and animal life" and call for "broadening the public interest therein and knowledge thereof." Management is by a cooperative effort by Arizona State Parks, the University of Arizona, and the private nonprofit corporation, which owns the physical facility. These three managing partners seek to maintain an appropriate balance between the public programs and academic endeavors. The Arboretum is primarily a service-oriented institution seeking to ascertain the types of plants that will thrive within the Sonoran Desert; displaying these and introducing them for use within the state and the Southwest; making seeds available to botanical gardens, arboreta, parks departments and government agencies; and offering a wide range of educational services dealing with plant science and biotic communities.

PUBLIC FACILITIES: The Arboretum is open daily year-round, except Dec. 25. During Fall and Winter months from October-through-April admission is taken from 8:00 a.m. to 5:00 p.m.; Summer hours during May, June, July, August and September are 6:00 a.m. to 3:00 p.m. Daily admission is $10 for adult; $5 for ages 5-12. Children under 5 years of age are admitted free. Annual memberships start at $50 for two people, $75 per family. Children must be accompanied by an adult at all times while on Arboretum grounds. Admission is usually waived one day each year - National Public Gardens Day in May.

The present Arboretum Visitor Center is located at the edge of the entry parking lot just off Highway 60. It was dedicated in October 1988 by Governor Rose Mofford and was in use by January, 1989. Designed by architect Less Wallach of Line and space, Tucson, the center incorporated a cooling tower and passive/active cooling and heating features. The Visitor Center contains a bookstore/giftshop, administrative offices, greenhouse, an orientation room and patios. Drought-tolerant plants, including cacti and other succulents, are made available for purchase by Arboretum visitors at the center.

The historic Smith Building, located a short distance downhill, was the original Visitor Center. Erected in 1925, it is constructed of rhyolite, a native stone quarried directly across Highway 60. It encompasses an Interpretive Center with museum exhibits and displays. Two public greenhouses attached to the Smith Building display living specimens of cacti and succulent plants brought together from many deserts.

The chief attraction at the Arboretum is the system of nature trails, with over two miles of combined length that weave through the botanical gardens. These gardens represent the "living museum" of plants capable of living in the Sonoran Desert of southern Arizona. Many are native species; others have been introduced. A series of Interpretive Ramadas are located along the Main Loop Trail to provide information to Arboretum visitors.

The Picnic Area is adjacent to Queen Creek and about 100 yards southeast of the Visitor Center. Shade is provided by an immense Arizona Sycamore tree, several large Athel (Tamarisk) trees and other species of shade trees. Picnic tables and grills are available for use. A Demonstration Garden is west of the Picnic Area. It exemplifies use of drought-tolerant plants for landscaping, and demonstration water-harvesting methods and irrigation techniques.

EDUCATIONAL GROUP LECTURES AND TOURS: Most visitors take two or three hours to explore the Arboretum using maps available at the Visitor Center. Guided tours can be arranged for groups of at least 20 or more people, provided sufficient notice is given. Appointments may be arranged by phone at 520.689.2723, or by email to lpacheco AT (substitute the @ for "AT" for this email to be valid).

The public may visit at any time in small groups. However, organized groups and classes are asked not to come without an appointment, since the facilities (including restrooms, parking lots, trails, etc.) can accommodate only the number of groups and classes that are ordinarily scheduled. Adult supervisors and an orientation session are required for classes below college or university level.

The Arboretum offers a series of public events each year, most of them included with daily admission. Our annual Bye-bye Buzzards Day is in September, seasonal Plant Sales are usually October and March, and November has both a Live Music Festival and our Fall Color Festival on Thanksgiving Weekend. Australia Day is in January, the Language of Flowers Show & Chocolate Tasting times to coincide with Valentines Day each February, our "Welcome Back Buzzards" festival is in mid-March and the Herb Festival in April. Seasonal weekend tours include bird-walks during Spring and Fall, "Plants of the Bible" tours and our "Edible/Medicinal Plants of the Desert walk. For complete event details visit our website or call the recorded message phone: 520. 689. 2811

Annual membership is a great way to support the Arboretum. "Friends of the Arboretum" enroll at levels starting at $50 to enjoy a full year's access and extra guest passes for friends or family. For complete information about benefits of membership call the Friends of the Arboretum at 520. 689. 5248 or else send an email to:

THE FOUNDER: William Boyce Thompson was born at Virginia City, Montana on May 13, 1869. He attended the School of Mines a Columbia University, becoming a mining engineer. He created a fortune by studying mines and selecting the most promising for development and investment. He was the founder and first president of Inspiration Consolidated Copper Company at Globe-Miami, Arizona and Magma Copper Company at Superior, Arizona.

Thompson received the honorary title of "Colonel" when he led a Red Cross expedition in 1917 to bring medical supplies, humanitarian assistance, comfort and advice to the Russian people who had just overthrown the Czar and who were still fighting Germany in the eastern theatre during World War I. He reached St. Petersburg after a long trip through arid parts of Asia. During this trip he became impressed with mankind's dependence on plants. He was struck by the fact that all food comes originally from plants. Although he encountered starvation and malnutrition, he was impressed by the many uses made of the rather scarce plants. During the trip he thought of creating an arid land arboretum where plants from the world's deserts could be brought together, catalogued, and their uses inventoried and their seeds distributed.

Colonel Thompson died on June 27, 1930. The Arizona Legislature stated that it was "profoundly appreciative" of the Boyce Thompson Southwestern Arboretum as a "scientific institution for the purpose of experimentation and research in the matter of native vegetation of the state and the Southwest."

ARBORETUM ACREAGE: Total land used by the Arboretum is 1,075.3 acres. Of this, a 726-acre tract (the north slope of Picketpost Mountain) belongs to the Federal Government. It has been used by the Arboretum as a restricted-access study area and nature preserve under a Special Use Permit from the Forest Service since it was fenced in 1929. Deeded land owned by the Boyce Thompson southwestern Arboretum, Inc., totals 329.75 acres along Queen Creek. This land includes the 100-acre tract of botanical gardens open to the public. A final tract of 20 acres south of U.S. Highway 60 and east of Picketpost House is owned by the University of Arizona

AYER LAKE: A storage reservoir designed to hold 3,680,000 gallons (10-acre feet) of water for irrigation was constructed in 1925. This was later named to honor Judge Charles F. Ayer, legal advisor to Colonel Thompson, who (with the Colonel and Attorney Edward W. Rice of Globe) was an original incorporator of the Arboretum. Ayer Lake is filled by means of pumps, one of which lifts water from Queen Creek over a steep intervening ridge.

MAJOR ACCOMPLISHMENTS: The Arboretum has established a collection of living plants composed of 3,201 different types of plants belong to 306 genera in 76 families. Work continues in evaluating plants for xeriscaping (desert region landscaping). In a cooperative study with the University of Arizona, oil pressed from seeds of a desert bush, Jojoba, was discovered to contain a liquid wax useful as a substitute for sperm-whale oil. Seeds of Jojoba have been extensively distributed to scientists and for industrial testing. This has resulted in large-scale planting of Jojoba on marginal farmland in Arizona as well as other arid climate areas.

The early work at the Arboretum in soil-retention by plant roots was instrumental in development of the U. S. Soil Conservation Service (SCS). The original Arboretum Director, Franklin J. Crider, left to become the first head of the Plant Materials Section of the SCS. As such he was one of the important "founding fathers" of the Soil Conservation Service. His original program was a cooperative one headquartered at the Arboretum and consisting of an interlocking project jointly accomplished by the Arboretum, the Forest Service, the Bureau of Indian Affairs and the Civilian Conservation Corps.

During World War II, the Arboretum distributed young cork oaks widely in the Southwest as a measure of emergency preparedness when the Nazi-Fascist interests threatened the world's cork supply.

Weather observations at the Arboretum, including precipitation and high and low temperature, have been faithfully recorded daily for over 75 years. Rainfall averages 17.0 inches per year, equally divided between summer and winter. Since 1965 guest quarters have been maintained, housing a variety of visiting scientists, researchers, lecturers and special guests. These scientists bring a wide range of studies appropriate to desert surroundings to the Arboretum. The Arboretum can provide housing, research facilities and logistic support for studies; to inquire about this call 520. 689. 2723.

Since the 1960s, Arboretum bird checklists have been made available to visitors. Because of the diverse habitats present, over 270 species of birds have been recorded here, including many rare and unusual migrants. Checklists for birds, mammals, and for reptiles and amphibians may be requested at the visitor center.

Updated: 6/1/09