By the 1960s, the ownership of the ranch was split between two of Karl and Augusta's sons, with Joe Iverson, an African safari hunter married to Iva Iverson, owning the southern half of the ranch (the Lower Iverson) and Aaron Iverson, a farmer married to Bessie Iverson, owning the northern half (the Upper Iverson). In the mid-1960s the state of California began construction on the Simi Valley Freeway, which ran east and west, roughly following the dividing line between the Upper Iverson and Lower Iverson, cutting the movie ranch in half. That separated the ranch, and also produced noise, making the property less useful for movie-making. The waning popularity of the Western genre and the decline of the B-movie coincided with the arrival of the freeway, which opened in 1967, and greater development pressure, signaling the end for Iverson as a successful movie ranch. The last few movies that filmed some scenes here included "Support Your Local Sheriff" (1968) and "Pony Express Rider" (1976).