Ethnically, the expedition members reflected Sonora and Sinaloa, the two areas from which most of the recruits had come. Of the 198 settlers who stayed in Alta California, 39 were adult male. The 1782 garrison lists of the San Francisco and San Diego presidios, identify six of these adult males as mulato (half Spanish and half African parentage), eleven as mestizo (mixed European and American Indian), and ten as español (persons of Spanish parentage, probably born in North America). These settlers represented a new racial and cultural group resulting from colonization of the New World.

The history of the Anza expeditions and the sites associated with them represent a vital portion of the Hispanic heritage of Arizona and California. The descendants of the expedition members, many of whom continue to live along the trail route, provide a direct link to the past. Landscape, place, and street names, architectural traditions, land use patterns, and other influences are still evident through much of the 1200-mile trail route. 

Natural Environment

Background
Physiography. The historic route passes through both the Basin and Range and the Pacific Border Physiographic Provinces. The Basin and Range Province, which covers the location of the historic route in Arizona and a small portion of the route in southern California, consists generally of numerous north-south trending mountain ranges interspersed with alluvial fan basins of various widths. Faulting and uplift are responsible in large part for the formation of the province's mountains and for the overall appearance of the terrain. 

The route passes through two sections of the Basin and Range Province, the Sonoran Desert and the Salton Trough. The Sonoran Desert section consists of widely separated short ranges in desert plains, while the Salton Trough includes desert alluvial slopes and the Gulf of California's delta plain.

The route through the Pacific Border Province passes through the California Coast and Los Angeles Ranges sections. The Los Angeles Ranges are characterized by narrow ranges and broad fault blocks, and alluviated lowlands. The California Coast Ranges, encompassing roughly the route from San Luis Obispo north to the Bay area, are characterized by parallel ranges and valleys on folded, faulted, and metamorphosed strata. 

Climate. The climate of the expedition route affected the timing of the trek (starting in October to avoid the desert heat), the route itself (following available water, forage, and fuel), and the well-being of the colonists. It will also influence visitor use.

The climate in the Sonoran Desert is hot and dry. Summer temperatures are extremely high, largely precluding midday active recreation, but winters are mild and ideal for all types of outdoor recreation. Although rainfall is universally low in the this desert, the timing of the precipitation differs significantly between eastern and western sections. 

In the Sonoran Desert in eastern Arizona, most of the rainfall occurs in the summer months due to storms originating in the Sea of Cortez. Rain also occurs in the winter due to general Pacific storms. As a result of its dual rainy season, this desert in eastern Arizona exhibits a range of plant and related animal life not found elsewhere in the Sonoran Desert. Western portions of the Sonoran Desert receive most of their precipitation in the months of December, January, and February.

Vegetation and Wildlife
Basin and Range. Vegetation in the Sonoran Desert is quite varied, but a common thread through the desert is the creosote bush. Found in most areas mixed with other shrubs and trees, the creosote bush does form pure stands in some areas. Other shrubs commonly found in the Sonoran Desert are burrobrush, brittlebush, and crucifixion thorn.
 

Ocotillo and creosote bush along the trail in Anza-Borrego Desert State Park, typical vegetation of the Basin and Range Province.

An unusual feature of this desert, contrasting particularly with the shrub-dominated deserts to the north, is the large variety of tree species. Among others are to be found the smoke tree, the desert willow, the paloverde, the ironwood, the elephant tree, and the honey and screwbean mesquite. Found in the better-watered drainages are willows, cottonwoods, and salt cedars. The latter is an introduced species, not present when Anza passed through the area, and is not a desirable part of local ecosystems. A few locations in the mountains surrounding the Salton Sea contain groves of the native California palm.

Although cacti are found throughout the Sonoran Desert, it is in the upland areas of Arizona, on the better watered and better drained slopes, that the cacti provide their most magnificent displays. The saguaro, rare west of the Colorado River, dominates the scene with its massive (up to 50 feet high) upright form. A wide variety of smaller cacti, including the cholla, the buckthorn, the beavertail, and the prickly pear, add to the ornamental garden atmosphere of the area. Ocotillos, yuccas, agaves, and a wide variety of flowering ephemeral plants complete the unique floral display of the region.

Although not always apparent to the casual visitor, the fauna of the Sonoran Desert is varied. Bird life exhibits a wide variety of both migratory and resident species. A common species of interest to many visitors is the roadrunner. Rodents dominate the assortment of mammals with a variety of rats, mice, and ground squirrels. Larger species include coyote, kit fox, gray fox, bobcat, mule deer, desert bighorn sheep, and the endangered Sonoran pronghorn, now limited to a few animals in extreme southwest Arizona. A species unique to the Arizona portion of the Sonoran Desert is the piglike javelina.

Among the wide assortment of amphibians and reptiles are found the now threatened desert tortoise and, confined to Arizona, the poisonous Gila Monster. The notable snakes of the region include several varieties of rattlesnake, the sidewinder, and the coral snake, which is limited to Arizona.

Pacific Border . Vegetation in the portions of the Pacific Border province traversed by the trail route is a mixture of chaparral, grassland, oak woodland, and riparian associations. Most of these native plant communities have been modified through grazing, soil cultivation, and urban development. Nonnative trees such as eucalyptus have been introduced and perennial native grasses (plants that have live roots year round) have been almost entirely supplanted by introduced annuals (plants which grow from seed each year). In the more natural sections of the trail route, native plant associations still persist.

These plant communities establish themselves in relationship to water availability, slope aspect, and elevation. Along streams at lower elevations is found the riparian (waterside) association including willow, alder, poplar, and sycamore. A typically dense understory of mixed vegetation provides valuable wildlife habitat. On drier, upper slopes, the oak woodland association is found. Species include blue oak, white oak, interior live oak, and coast live oak. Depending upon the canopy cover, brush or grass may be the understory. Acorns provide food for wildlife, and the plant association offers a variety of wildlife niches. Wildfire has been a continual influence on the oak woodland. On the highest slopes, on the driest southwest aspects, occurs   the chaparral association. Major species include toyon, scrub oak, coyote brush,

Typical oak grassland and agricultural landscape in California. Photo taken in the Salinas Valley looking toward the Santa Lucia Range. The Anza expedition followed the Salinas River at the base of the foothills. chamise, sage, buckwheat, manzanita, ceanothus, monkey flowers, and poison oak. This vegetation type is also prone to high fire frequency (O’Keefe, 1993).

Much of oak woodland and chaparral vegetation types have been converted to ranch or dryland agriculture or cleared for home sites. The native understory bunch grasses such as deer grass, purple needlegrass, California oatgrass, and nodding stipa have been replaced by mostly Mediterranean imports such as softchess, red brome, Italian ryegrass, foxtail, and annual bluegrass (Weitkamp, 1993).

Plant and animal species composition in the urbanized portions of the Anza route have been significantly altered from natural conditions. In the more natural areas, common wildlife species in the oak woodland and chaparral associations include bear, deer, cougar, coyotes, possum, raccoons, and foxes. In addition, there is a variety of herps, including frogs and snakes, large birds such as turkey vultures, owls, and hawks, and smaller birds such as quail and redwing. 
 

Vegetation grows in the soft bottom of the Los Angeles River channel along the Anza Trail route in the Griffith Park area.

Floodplains and Wetlands Since the Anza Trail generally follows major river corridors, it is frequently within floodplains or former floodplains and skirts wetlands or former wetlands. Within Arizona, most of the trail is aligned along the Santa Cruz or Gila Rivers. Historically, these rivers flowed alternately above and under ground and spread out in large floodplains rather than having defined channels. Land use and management from the Spanish period to the present — livestock, agriculture, and associated ground water pumping, flood control and water storage for residential and urban uses — have affectedthese rivers by creating defined channels and often reducing flows. In the case of the Santa Cruz River, pumping had stopped river flow by the middle twentieth century. In the 1970s, flow was restored to the lower Santa Cruz through discharge from the Nogales International Wastewater Treatment Plant in Rio Rico.

San Felipe Wash is generally natural and protected within state parks or federal areas. The headwaters of Coyote Creek are within Henry W. Coe State Park, but it flows mostly through several local jurisdictions and private lands. The San Jacinto River outlet has been changed, affecting Mystic Lake, a large wetland which Anza named Laguna de Bucareli. The Los Angeles River is largely channelized, although some naturalized areas exist. The San Antonio River and Nacimiento have been dammed to create San Antonio Reservoir. The Salinas River remains free-flowing alternately above and below ground, spreading out seasonally in large flood plains rather than having a defined channel. It is affected by agricultural and ranching uses along its banks.

Many more wetlands existed at the time of the expedition than today. Generally, wetland areas have been drained and put to agricultural or urban uses. The following three wetlands have achieved some measure of protection along the historic route: San Sebastian Marsh at the confluence of Carrizo Wash and San Felipe Creek, a National Natural Landmark administered by the Bureau of Land Management; Mystic Lake, which is adjacent to the San Jacinto Wildlife Area administered by the California Fish and Game Department and a high priority acquisition area for that department; and San Francisco Bay, portions of which are protected by private landowners and local, regional, state, and federal agencies.

Threatened and Endangered Species
Threatened (T) or endangered (E) animal and plant species may exist almost anywhere along the Juan Bautista de Anza National Historic Trail and definitely do occur within some of the more historically significant sections of the trail. For instance, the flat-tailed horned lizard (T) habitat exists along the Anza route in Imperial County. The California peninsular bighorn sheep (T) and least Bell's vireo (E) are known to exist within the desert portion of the trail in San Diego County. Other species of state concern in that area are southwest willow flycatcher (E) and Gander's cryptantha. (San Diego County task force, 1993) The trail runs through Stephens' kangaroo rat habitat in Riverside County. (Riverside County task force, 1993) The California brown pelican (E), American peregrine falcon (E), southern bald eagle (E), California least tern (E) as well as several candidate species exist along the trail route in Santa Barbara and San Luis Obispo Counties from Gaviota through the Nipomo Dunes area. (Interface, 1990; San Luis Obispo County task force, 1993) The Camp Roberts area in San Luis Obispo and Monterey Counties contains habitat for the San Joaquin kit fox (E) and candidate species pale-yellow layia, Nuttall's scrub oak, black-flowered figwort, and San Ynez false lupine (Letter #13 , from Camp Roberts, page 120).

T & E species that may occur within the trail corridor are listed in Appendix M. Within Arizona, seven federal endangered species, one proposed federal endangered species, two Candidate Category 1, and 22 Candidate Category 2 species may occur within the trail corridor. In addition, the state has identified three endangered, four threatened, and five candidate species. Threatened and endangered plant communities that have been identified by the state and that may occur along the trail include cottonwood/willow and mesquite bosques. 

In California, 30 federal endangered species and seven federal proposed endangered species, four threatened, 33 Candidate Category 1, and 74 Candidate Category 2 species may occur within the trail corridor. Rare plant communities are native grassland, wildflower field, central coast cottonwood-sycamore riparian forest, central coast live oak riparian forest, and central coast arroyo willow riparian association (San Luis Obispo County Task Force Report, May 1993).

Land Ownership and Use
In Arizona, most of the historic route traverses lands that are privately owned, either in individual ownerships or, in the case of the American Indian reservations, in collective trust for the tribes. The route does traverse some sections of state lands and some areas of federal lands under administration of the Bureau of Land Management.

The predominant land uses along the route in Arizona include livestock grazing, transportation facilities, irrigated agriculture, and the range of residential, commercial, and industrial uses associated with urban concentrations. Urban areas along the route include Nogales, Tucson, and Yuma.

Land use along the route in California is much the same as in Arizona. Lands are for the most part privately owned, and the range of land uses includes grazing, irrigated agriculture, various urban uses, and transportation facilities.

Public lands traversed by the historic trail alignment in California include the Golden Gate National Recreation Area managed by the NPS, lands managed by the Forest Service and Bureau of Land Management, several units of the California state park system, and several military installations as described below.

Only a small portion of National Forest land, Bautista Canyon through the San Bernardino National Forest, is traversed by the route. A larger segment of the route passes through Bureau of Land Management lands located between the international border and the Salton Sea.

Several miles of the historic route pass through Anza-Borrego Desert State Park, on the northeastern edge of San Diego County, and through Henry W. Coe State Park, located southeast of San Francisco Bay in Santa Clara County. In addition, the route passes through smaller units of the state park system, including Perris Lake State Recreation Area, Ocotillo Wells State Vehicular Recreation Area, and several beach parks along the Santa Barbara channel.
 

Grazing land along San Juan Grade  Road in San Benito County, the  historic Anza route

The route crosses various federal military reservations in California. These include March Air Force Base, located in Riverside, Vandenberg Air Force Base, located on the coast of northern Santa Barbara County, Fort Hunter Liggett, located inland in the central coast region, and Camp Roberts, located inland in the central coast region. Camp Roberts is owned by the Department of the Army and leased to the California Army National Guard. The historic route also crosses the El Centro Naval Gunnery Range located in Imperial County on land leased from the Bureau of Land Management.

Even though the populations of Maricopa, San Diego, and Imperial Counties are significant, the trail alignment within these counties is almost entirely within unpopulated areas. However, within San Diego and Imperial Counties the areas the trail traverses attract significant numbers of recreational users from the nearby urban areas. Adding the populations of the counties, the trail corridor is within a few hours drive of approximately 23.7 million people.

TABLE 8: POPULATION GROWTH BY COUNTY
 

	1990  Population	Percent Change 1980 - 1990
ARIZONA
MARICOPA	2,122,101	41%
PIMA	666,880	25%
PINAL	116,379	28%
SANTA CRUZ	29,676	45%
YUMA	106,895	40%
CALIFORNIA
ALAMEDA	1,279,182	16%
CONTRA COSTA	803,732	23%
IMPERIAL	109,303	19%
LOS ANGELES	8,863,164	19%
MONTEREY	355,660	23%
RIVERSIDE	1,170,413	77%
SAN BENITO	36,697	47%
SAN BERNARDINO	1,418,380	59%
SAN DIEGO	2,498,016	34%
SAN FRANCISCO	723,959	07%
SAN LUIS OBISPO	217,162	40%
SAN MATEO	649,623	11%
SANTA BARBARA	369,608	24%
SANTA CLARA	1,497,577	16%
VENTURA	669,016	26%
TOTAL POPULATION	23,703,423

Sources:
1990 Census of Population and Housing Units, California, Bureau of the Census, US Dept. of Commerce, 1993.
1990 Population Change in Arizona: 1980-1990, Arizona Department of Economic Security, Population Statistics Unit, 1991.