Carter BloodCare's O-negative blood supply stands at less than one day for area hospitals.

The Bedford-based nonprofit is bringing its mobile bus to four locations across southern Denton County in October, including a seven-hour drive at Flower Mound High School on Wednesday, Oct. 21. The schedule, first reported by the Cross Timbers Gazette, gives area residents multiple chances to donate close to home.

Blood is in high demand to support local patients undergoing cancer treatments and surgeries, according to Carter BloodCare. The organization's website listed O-negative at "Critical Need" as of Sept. 29, meaning the community supply could serve hospitals for less than one day. Platelets, B-negative and A-negative were at "Urgent Need," with two to three days of supply remaining.

Here is the full October schedule:

Monday, Oct. 5 — Denton County Southwest Courthouse, 6200 Canyon Falls Drive (Community Room), Argyle. 10 a.m. to 2 p.m. Coordinator: Efrain Frias. Register here.

Sunday, Oct. 18 — St. Mark's Catholic Church, 6500 Crawford Road, Argyle. 7:45 a.m. to 1 p.m. The Carter BloodCare bus will be on-site. Sponsored by the Knights of Columbus Ralph Cerny Council #12553. Coordinator: Tim Schoendorf. Register here.

Wednesday, Oct. 21 — Flower Mound High School, 3411 Peters Colony Road, Flower Mound. Noon to 7 p.m. Coordinator: Jennifer Owens. Register here.

Wednesday, Oct. 28 — Argyle Community Church Student Center (Fellowship Hall), 414 US-377, Argyle. 7 a.m. to noon. The Carter BloodCare bus will be on-site. Hosted by the Argyle Lions Club. Coordinator: Seth Alexander. Register here.

The Oct. 21 drive at Flower Mound High School offers the widest window for donors who work during the day, running until 7 p.m.

Carter BloodCare ran similar drives in the area in September, including stops at Texas Health Presbyterian Hospital in Flower Mound and Denton County ESD No. 1 in Argyle. No November dates have been announced. Donors can check Carter BloodCare's website for future opportunities.

The first drive is Monday, Oct. 5, at the Denton County Southwest Courthouse in Argyle.