Keller Loader, the first three-wheeled loader built by brothers Louis and Cyril Keller for Eddie Velo, a turkey farmer whose barns needed cleaning. The Keller Loader has a rear caster wheel and two drive wheels with an innovative clutch drive mechanism and is powered by a 6 hp Kohler engine. The Keller brothers build six more loaders at their Rothsay, Minnesota, machine shop before being introduced to the Melroe brothers in 1958.

The Melroe brothers invite the Kellers to demonstrate their loader at the Melroe farm equipment exhibit at the Minnesota State Fair. The loader is an instant hit, and before the fair was over the Melroes invited the Kellers to join them. After reaching a royalty agreement on their clutch drive design, the Kellers are hired to design a new loader and bring it to production at Melroe Manufacturing Company in Gwinner, North Dakota.

M60 Melroe self-propelled loader is an improved version of the Keller loader with a larger 9 hp engine and improved lift arm geometry, sometimes called the “grasshopper boom” design -- 17 are built.

M200 is the second design of the Melroe self-propelled loader, with a 12.9 hp Onan engine. The lift arms are again redesigned, giving the loader 750 lb. rated capacity -- 400 are built.

M400 is adapted from the M200 by adding a rear axle. With four-wheel drive, it is the world’s first skid-steer loader. Some 200 M400s are built. What makes the skid-steer unique is the use of two independent transmissions that allow it to turn in its tracks. The new loader is 6 inches longer than the M200 and – with some tweaking – will eventually achieve a 70-30 front to rear weight ratio for optimal skid-steer performance.

M440 is the first Bobcat-branded skid-steer loader. With a 15.5 hp Kohler 2-cylinder engine, it has a rated capacity of 1100 lb. It is a totally new design, with the drive system enclosed in side tanks that feature an oil bath for lubrication. The design change allows the operator to enter the loader from the front.

M444 replaces the M440 less than a year later, with the addition of pressure-oiled clutches for better durability.

M500 delivered more power with a 24 hp Kohler K662 gas engine.

M500E is adapted with a 10 hp electric motor, allowing grain elevators to use the loader inside boxcars and in other dusty environments. A retracting cable reel allows the machine to work within a radius of about 50 ft.

M600 has a Wisconsin VF4D gas engine. It is built until 1975. A vertical forklift mast option makes it popular with bricklayers.

Cyril Keller demonstrates the loader, which was developed in secret by his brother, Louis. It is introduced the following year with an overhead guard (or ROPS) and given the model designation M371, powered by a 14 hp Kohler engine.

M610, with a Wisconsin gas engine and 1,000 lb. rated capacity, will remain the most popular Bobcat model for the next decade. When the last M610 rolls off the assembly line in 1982, it signifies the end of the clutch-drive loader and the transition to diesel powered equipment.

1074 Bobcat feller buncher, a tree-harvesting machine with a shear attachment that can cut, bunch and transport trees. Over the next decade, several different models are built -- including the 1080 and an innovative six-wheel drive model 1213 -- but the product line is discontinued in 1987.

825 Bobcat, with a rated capacity of 1,500 lb., continues the trend toward larger, diesel-powered machines. It is discontinued in 1983, replaced by the new B-Series 843.

520 is the first of the “B-Series” design, a complete makeover of the Bobcat loader line. The goal was to make many components -- operator cabin and ROPS, seat, steering levers, pedals and tailgate -- interchangeable among several frame sizes. Such design standardization will allow more efficient mass production of the Bobcat loader in the Gwinner factory.

New Breed 30 Series launches, including models 530, 533, 630, 631 and 632 with gas and diesel, air- and liquid-cooled engines. A major product feature is its center-mounted chaincase with drive chains in a “bowtie” configuration, which eliminates adjustments, a highly touted competitive advantage. Models 730, 731, 732 arrive the next year.

The new “Bauhaus” Bobcat logotype is unveiled with the cathead symbol that is still used today.

Articulated loader, called “the Bobcat that bends in the middle,” diversifies the loader lineup. A rough-terrain forklift version -- the 2000RTF -- is introduced a year later. The market for articulated loaders doesn’t grow as expected and the line is discontinued in 1995.

40 Series Bobcat 743 launches and quickly becomes the world’s most popular skid-steer loader. At its peak in the late 1980s, the production of the diesel-powered 743 represents half of all Bobcat loader factory output. The 40 Series loaders are the first to incorporate the new Seat Bar operator safety system. Other 40 Series models include the 540, 542 and 543; the 641, 642 and 643; the 741, 742 and 743; and the 843.

After the early 1980s recession, company management makes a conscious effort to keep from raising prices on its Bobcat loader line. The strategy lasts 10 years and, much to the dismay of competitors is touted in ads saying, “Still at 1983 Pricing.” As a result, the skid-steer loader becomes a cost-effective solution of choice across many industries, unseating the once-popular tractor loader backhoe.

440 and 443 are the first to have a transversely mounted engine. The newest Mini-Bobs replace the 310 and 313 and are still 3 ft wide and 6 ft tall.

943 is the second Bobcat loader with the engine mounted transversely, allowing the hydrostatic drive pumps to be belt-driven for more efficiency, lower noise and easier service access for routine maintenance. This transverse engine design is repeated on succeeding loader generations and continues today.

Next Generation “50 Series” 753 and 853 models introduced, with an innovative electronic monitoring and diagnostic system called “BOSS,” a dual path cooling system, protected axle bearings and a single tilt cylinder.

7753 is the first of the Bobcat vertical lift path loaders that would revolutionize the line. Its vertical path boosts lift capacity without increasing machine weight. These new loaders are called ideal “lift-and-carry” machines.

Long wheelbase 753L (later renamed 763) gains a bit of lift capacity by increasing the distance between the front and rear axles without sacrificing its characteristic skid-steer maneuverability.

873 marked the transition of the larger frame size loader to vertical lift path.