Unit 37A

The Tortolita Mountains dominate the western portion and offer glassing from ridges overlooking the bajada. The Sawtooth Mountains and Picacho Mountains provide distinctive navigation landmarks and higher-elevation refuge. Santa Cruz Flats stretch across the central basin—broad, open country for spotting game movement.

The Santa Cruz River and its associated washes provide the primary drainage corridors. Cottonwood Spring, Bass Spring, and Cochie Spring mark reliable water locations. Gap Tank, Picacho Reservoir, and Silver Bell Tailings Pond offer additional water reference points for route planning.

Elevations range from around 1,400 feet in the basin floors to roughly 4,700 feet on the highest ridges—a span that keeps the entire unit in lower desert and transition zone. Most country sits below 3,000 feet as open creosote-bursage bajada and salt bush flats. Mountain slopes, particularly on ranges like the Tortolitas, Sawtooth, and Picacho mountains, climb through sparse palo verde and saguaro cactus with scattered juniper on the upper slopes.

This is primarily shrubland and open desert; expect minimal forest cover and long sight lines across the valleys.

Nearly 2,850 miles of road crisscross the unit, making it well-connected but also well-traveled. I-10, Highway 87, Highway 79, Highway 287, Highway 86, and Highway 77 bisect the unit, creating multiple entry points and easy access for casual hunters. Most pressure concentrates near these highways and within a few miles of reliable water.

The vast bajada country between ranges sees lighter pressure. Marana, Picacho, Florence, and Silver Bell serve as logical staging points. Private land checkerboarding requires constant attention to boundaries, especially near populated areas.

Unit 37A encompasses roughly 2,600 square miles of lower desert bounded by I-10 to the north and east, Arizona Highway 287 and Highway 79 to the northeast near Florence, Highway 77 to the east, and the Tohono O'odham Nation boundary to the south and west. The unit wraps around the western suburbs of greater Phoenix, with access corridors along I-10 and multiple state highways. The geography is dominated by broad basins and bajadas interrupted by low to moderate mountain ranges, creating a checkerboard of public and private land requiring careful route planning.

Water is genuinely limited here; most drainages run seasonally. The Santa Cruz River is the major surface drainage but unreliable year-round in many sections. Named springs—Cottonwood, Bass, and Cochie—mark critical water locations, especially during spring and summer hunting.

Washes like Sahuarita, Suffering, Silver Bell, and Tom Mix run intermittently. Several reservoirs and tanks exist (Picacho, Gap, Big Tank, Sasco Tank), but reliability varies seasonally. Hunters must verify water status before committing to backcountry travel.

Early morning glassing of likely water sources often yields game sightings.

Unit 37A supports mule deer, white-tailed deer, pronghorn, desert bighorn sheep, mountain lion, javelina, and occasional black bear. The bajadas and lower slopes are pronghorn and mule deer country; expect early-season distribution across open ground near seasonal water. Deer hunting peaks during cooler months when animals move more actively.

Desert sheep country concentrates on the steeper mountain ranges, particularly the Tortolitas and Sawtooth Mountains—mountain terrain hunting requiring early starts and glassing from distance. Javelina inhabit bajada and lower canyon country year-round. Water sources dictate movement; plan hunts around verified springs and tanks.

The low relief complexity means routes are straightforward, but the scale and heat demand physical fitness and water management.