Diablo Holdings, Ltd.  is a Property & Asset Management Company representing The Lineweaver Trust, a private investment company. Diablo Holdings, Ltd., a California corporation, employs a staff of 10 in its Berkeley and Alamo (Contra Costa County) offices, and manages real estate assets in Alameda and Contra Costa Counties.

Diablo Holdings was originally formed in 1972 under the name Bay Cities Realty, and the company name was changed in 1974 to Diablo Holdings, Ltd.  The company was incorporated in 1979, as company interests expanded throughout the 1980’s and 1990’s to include investments in other businesses, involving out-of-state real estate, mining and quarrying interests, and an import/export company.  Diablo also provided operational management for a non-profit organization, The Danny Foundation for Crib and Child Product Safety, which dissolved in 2005.  Diablo Holdings, Ltd. is a wholly owned subsidiary of The Lineweaver Trust.

John L. Lineweaver

John L. Lineweaver is a 42 year veteran of the real estate industry, having obtained his California Real Estate License in 1969. After working as a loan officer in the construction lending department of a major national bank, he formed Bay Cities Realty in 1972, and was involved in numerous traditional commercial and multi-family brokerage transactions over the ensuing 2 years. In 1974, Mr. Lineweaver formed Diablo Holdings, Ltd., and changed his focus from brokerage to development, specifically to the purchase and renovation of commercial and multi-family residential buildings. To accommodate the Property Management aspects of his business, Mr. Lineweaver incorporated Diablo Holdings, Ltd. on July 10, 1979, as a California corporation. Diablo Holdings, Ltd currently oversees 9 employees, and is wholly owned by The Lineweaver Trust, of which Mr. Lineweaver is Co-Trustee.

Over the past 40 years, John Lineweaver, through Diablo Holdings, Ltd., has developed, renovated, owned and managed office, retail and residential properties, ranging from single family homes to a 92,000 square foot, 4-building office complex. Currently, Diablo Holdings manages nearly 150,000 square feet of retail and office space.

Mr. Lineweaver has also founded and managed a diverse set of businesses outside of the real estate industry. In 1986, Mr. Lineweaver co-founded Table Mountain Quarry, a start-up rock and gravel quarrying operation in Northern California. Mr. Lineweaver was Chief Financial Officer of the Corporation for seven years, and oversaw the design, purchase and installation of several million dollars worth of quarry operating equipment, as well as a complex Environmental Impact Report process. In 1996, while retaining royalty rights, Lineweaver sold Table Mountain Quarry to Martin Marietta Materials, which extended the quarry’s mining permit to 2029, and re-sold the Quarry to Vulcan Materials, Inc.

In 1988, Mr. Lineweaver co-founded Unique Quilts, Inc., an import/export company which initially designed, manufactured and imported handmade quilts and related products from mainland China. The company was sold in 1993.


Mary Ann Wallace
Vice President-Administration

Mary Ann Wallace is a 28 year employee of Diablo Holdings, Ltd., currently holding the title of Vice President, Personnel Administration.  After 24 years, she changed from a full time position to part time.    Her prior real estate related knowledge and experience was developed in class courses in real estate escrow and practical experience with Mason McDuffie Residential Real Estate, at the Downtown Danville office, during the 1970’s and early ‘80’s.

As Diablo Holdings grew in the late 1980’s and 1990’s, acquiring new commercial and residential properties, the additional work associated with Property Management necessitated the hiring of a Property Manager, resident managers, bookkeeper, additional secretarial support, warehouse and maintenance personnel.  In the role of Personnel Administrator, Wallace is responsible for posting employment opportunity ads and screening potential applicants.  She is proud of Diablo Holdings tremendous success in retaining many staff members continuously for over 15 years, and those who have moved on, did so due to transfer, relocation or retirement.

She has been key to the development and staffing of other former business ventures affiliated with Diablo Holdings, and non-profit entities, including operations of an Executive Offices Center, a rock quarry and an import company.  When the Lineweaver family established The Danny Foundation, a 501(C)(3) Non Profit Corporation in 1986, it became one of the most challenging and rewarding experiences of her life, where she served as a member of its Advisory Board and a dedicated Volunteer throughout its 20 years of national service in educating the public about the unknown dangers of unsafe baby cribs.  With the foundation’s original mission fulfilled, it disbanded at the end of 2005.

Wallace, a native Californian, together with Wes, her husband of 48 years, raised their sons in Contra Costa County.  Their sons both enjoy professional careers – Roger, in the computer networking technology field, and Erik in Health and Medicine.  They are the proud grandparents of two delightful granddaughters, Jordan and Alexa.


Andy Lineweaver
Vice-President, Property Management

Andy Lineweaver is the Vice President, Property Management of Diablo Holdings, Ltd.    He received an AA degree in Business from Diablo Valley College in 1986,  and studied at California State University at Northridge from 1986-1988. He has been with Diablo Holdings since 1989, and began with the company as an apprentice to the Property Manager.  He soon took on most responsibilities of management, including the daily operations and maintenance of all properties, as well as all construction and renovation projects and tenant improvement installations.  He is very proud and confident in the 5 staff members that he supervises and consequently most commercial and residential tenant improvement projects and daily maintenance activities are done “in-house”.

Andy is the father of two wonderful kids and the lucky husband to his wife of 19 years, Amber.  In his spare time he loves to go on weekend Tahoe trips with his family.  He also enjoys coaching his daughter and son in various sports, including baseball, softball and soccer, where he has a class D coaching and referee license.


Linda DeVenney

Linda DeVenney was born and raised in Southern Oregon. In 1971, she earned a Bachelor’s degree in Sociology from Southern Oregon University and was listed in Who’s Who Among Students in American Universities and Colleges. Her primary career focus changed when she married her husband, Scott, and moved to California to allow him to pursue his career as an actor. Working first for Ryder Truck Rental then Continental Baking (Wonder Bread, Twinkies, and Ho Ho’s), it became apparent that bookkeeping/accounting jobs paid the bills a lot better than volunteer work. After taking accounting classes at Diablo Valley College, Linda was able to successfully market herself as a bookkeeper, giving her the time and flexibility needed to both raise a son, and remain active as a community volunteer. She worked as a full-charge bookkeeper for several firms until 1994 when she began her career at Diablo Holdings, Ltd. It was a perfect fit; giving her the ability to keep herself in the bookkeeping/accounting field while staying active with her community volunteer work.

In 1998 she joined the Board of Directors of the Danny Foundation, was soon elected Secretary and served in that position until the Foundation was dissolved in 2005. Linda has served as President of Cambridge Elementary Parent Teacher Association, was a Den Leader for her son’s Cub Scout Den, and Treasurer for Boy Scout Troop 444. She has helped many boys on their trail to Eagle Scout, including her own son, Lance. Linda is currently a volunteer with the Clayton Library Foundation, Merit Badge Counselor and Committee Member with Troop 444. She also serves as Chairperson of Muir District’s Eagle Scout Boards of Review for the Mt. Diablo/Silverado Council. In 2006 she received the Muir District Award of Merit in recognition of her years of service to the Boy Scouts of America.

Linda lives in Clayton with her husband and two cats. Their son, Lance, resides in Oregon,  and foster daughter, Jillian in So. California, where she & husband Jerry are raising their young daughter. In her spare time she enjoys gardening, collecting cookbooks and cooking.