On December 16, 1957 an agreement was made between the government of British Honduras and a delegation of the Quellen Colony in Chihuahua and Durango in Mexico. In this agreement, British Honduras granted the Mennonites the right to run their own churches and schools, with their own teachers, in their own language, according to their religion. And also the privilege of affirming with the simple ‘yes’ or ‘no’ instead of making oaths in or out of the courts. And the right to administer and invest the estates of their own people, especially those of widows and orphans, in their own ‘Trust System’, called the ‘Waisenamt’, according to their own rules and regulations; Also the exemption from any social security or compulsory system of insurance. In return the Mennonites agreed among other things to bring into British Honduras capital investment amounting to 500k British Honduras dollars and to produce food not only for themselves but also for local consumption.

One of the reasons that George Price invited the Mennonites to Belize was to lessen their economic dependence on neighbouring countries.

In 1958 the Kleine Gemeinde Mennonites from Quellen Colony moved to Belize, creating the Spanish Lookout and Blue Creek settlements. They objected to a new social welfare law in Mexico and arable land was available in Belize. In 1966 over 30 conservative families left the settlement for Paraguay due to conflicting beliefs about modernization. Another group also left the colony and started a new colony in Lower Barton Creek. Nevertheless, the settlement's population of 1,108 in 1987 has tripled until 2022 through natural growth, it has grown to over 3,100 inhabitants.

In the 1980s, refugees arrived from Guatemala and El Salvador, settling in surrounding villages, finding employment and schooling for their children within Spanish Lookout.

Spanish Lookout specializes in auto parts and is Belize's main supplier of tires and steel imports. It is also a major producer of dairy, poultry, vegetables and cattle produce. Spanish Lookout is home to some of the largest companies in Belize, including Quality Poultry Products (Chicken), Western Dairies (Milk), Country Foods (Eggs), Koop Sheet Metal (Roofing), Country Meats (Beef, Pork etc.) and Bel-car Exports (Corn and Beans).

As of 2006, Spanish Lookout has the only commercial oilfield within Belize.