From the plaque:
Spanish missionaries introduced
the principle of irrigation in San Bernardino Valley,
thus opening the way to settlement. Franciscan fathers
engineered, and Indians dug, this first ditch (or 'zanja')
in 1819-20. In historical sequence the zanja supported the San Bernardino Asistencia,
Rancho San Bernardino, pioneer ranches, orchards
and Redlands' domestic water supply.
Plaque placed by the California State Park Commission in cooperation with Redlands Kiwanis Club, City Park Department, and San Bernardino County Museum Association, 1965.