The city is accessible from Interstate 10, which geographically traverses the city from north to south. The Sandalwood Fire, which started October 10, 2019, burned for five days. However, development of these large tracts have been slow to move forward until the demand increases. The number of approved units currently outnumbers the total population within the city. The previous decade saw several planned communities approved for development within the city, including the JP Ranch Development (approximately 750 total homes), Calimesa Springs Development (approximately 270 homes), Summerwind Ranch at Oak Valley (3,841 homes, 260 acres of mixed-use commercial), and Mesa Verde (3,500 homes, and 64 acres of mixed-use commercial space). Prior to its incorporation, the City of Calimesa existed as an unincorporated census designated town that straddled the Riverside–San Bernardino County line at the location where Interstate 10 climbs the San Gorgonio Pass going eastward from Redlands, California. The City of Calimesa was incorporated on December 1, 1990, soon after the incorporation of its northern neighbor, the City of Yucaipa. Calimesa community members felt the need for more protection on the south side of the wash, so in 1949 they formed the Volunteer Fire Department. Prior to 1949, the fire protection for the valley was provided by the California Department of Forestry at the Avenue A station, which today is the office of County Service Area 63 in Yucaipa. The Improvement Association and the Chamber have operated as a mix of promoting Calimesa, providing community service, and being a sounding board for residents’ problems. In 1962, the Calimesa Improvement Association became the Calimesa Chamber of Commerce. The "South Mesa Water Company" purchased the land for a well site and allowed the association to use it for community events. Volunteers built a community center at the corner of Bryant and Avenue H, which had been designated a park site by the Redlands-Yucaipa Land Company. According to the constitution of the association, “The object and purpose of the association shall be the development and improvement of Calimesa and The Community”. In 1939 or 1940, the Calimesa Improvement Association, Inc. The post office reinforced the residents' feeling of a community separate from the town of Yucaipa.
A site within the rancheria, the location of the present Highland Springs Ranch & Inn, along with Whitewater, and a house at the east end of present-day Singleton Road in Calimesa, all became stage stops along this path. The San Gorgonio rancheria covered most of the San Gorgonio Pass area. The Assistencia in Redlands (which has been rebuilt), and Rancho San Gorgonio, were part of the San Gabriel Mission located near today's Los Angeles. As early as 1820, reference can be found to the messenger footpath for the missions in Arizona to the San Gabriel Mission. The need for a land route to these missions inspired Captain Juan Bautista de Anza to lead a party through the area in 1774. The modern history of the area was initiated with the establishment of Spanish missions in Alta California in 1769. Calimesa was chosen from 107 names submitted, and is said to come from “cali” (referring to California) and “mesa” from the Spanish word meaning "table" or "table-lands." The first post office was the grocery store at Calimesa Boulevard and Avenue K. In June 1929, nearly 100 residents attended a meeting and decided to apply for their own post office and to start a “name contest” in which the winner was paid $10.
Route 99 (modern day I-10), businesses opened and Calimesa began to take on a separate identity from the larger neighboring town of Yucaipa. Historically, Calimesa began as a small rural town with mostly single-family homes and ranches. See also: List of Riverside County, California, placename etymologies: Calimesa